| IA Control | CCI | SRGID | STIGID | SRG Requirement | Requirement | SRG VulDiscussion | Vul Discussion | Status | SRG Check | Check | SRG Fix | Fix | Severity | Mitigation | Artifact Description | Status Justification | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-90176-9 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/sudoers. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
The actions taken by system administrators must be audited to keep a record of what was executed on the system, as well as for accountability purposes. Editing the sudoers file may be sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers" with the following command: $ sudo auditctl -l | grep /etc/sudoers -w /etc/sudoers -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 1 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-89498-0 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/sudoers.d/ directory. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
The actions taken by system administrators must be audited to keep a record of what was executed on the system, as well as for accountability purposes. Editing the sudoers file may be sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/" with the following command: $ sudo auditctl -l | grep /etc/sudoers.d -w /etc/sudoers.d/ -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers.d/ -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 2 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-83722-9 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications must be investigated for legitimacy. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group" with the following command: $ sudo auditctl -l | egrep '(/etc/group)' -w /etc/group -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/group -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 3 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-83723-7 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow" with the following command: $ sudo auditctl -l | egrep '(/etc/gshadow)' -w /etc/gshadow -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/gshadow -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 4 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000503-CTR-001275 | CCE-83712-0 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/opasswd. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/security/opasswd" with the following command: $ sudo auditctl -l | egrep '(/etc/security/opasswd)' -w /etc/security/opasswd -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/security/opasswd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/security/opasswd -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 5 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000304-GPOS-00121,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-OS-000274-GPOS-00104,SRG-OS-000275-GPOS-00105,SRG-OS-000276-GPOS-00106,SRG-OS-000277-GPOS-00107,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-83714-6 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd" with the following command: $ sudo auditctl -l | egrep '(/etc/passwd)' -w /etc/passwd -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/passwd -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 6 | CCI-001403,CCI-001404,CCI-001405,CCI-000172,CCI-000130,CCI-002130,CCI-000135,CCI-000169,CCI-002884,CCI-000018,CCI-000015 | SRG-OS-000004-GPOS-00004,SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000304-GPOS-00121,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000470-GPOS-00214,SRG-OS-000471-GPOS-00215,SRG-OS-000239-GPOS-00089,SRG-OS-000240-GPOS-00090,SRG-OS-000241-GPOS-00091,SRG-OS-000303-GPOS-00120,SRG-OS-000466-GPOS-00210,SRG-OS-000476-GPOS-00221,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000503-CTR-001275 | CCE-83725-2 | The operating system must audit all account removal actions. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow. | When operating system accounts are removed, user accessibility is affected. Accounts are utilized for identifying individual users or for identifying the operating system processes themselves. In order to detect and respond to events affecting user accessibility and system processing, operating systems must audit account removal actions and, as required, notify the appropriate individuals so they can investigate the event. Such a capability greatly reduces the risk that operating system accessibility will be negatively affected for extended periods of time and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. | Applicable - Configurable | Verify the operating system automatically audits account removal actions. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd with the following command: $ sudo auditctl -l | egrep '(/etc/shadow)' -w /etc/shadow -p wa -k identity If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/shadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/shadow -p wa -k identity The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 7 | CCI-000133,CCI-001881,CCI-001875,CCI-000154,CCI-001882,CCI-000158,CCI-001914,CCI-000169,CCI-001464,CCI-001878,CCI-001877,CCI-001889,CCI-000135,CCI-002884,CCI-001487,CCI-003938,CCI-000132,CCI-004188,CCI-000134,CCI-000172,CCI-000130,CCI-000131,CCI-001879,CCI-001880,CCI-001876 | SRG-OS-000062-GPOS-00031,SRG-OS-000037-GPOS-00015,SRG-OS-000038-GPOS-00016,SRG-OS-000039-GPOS-00017,SRG-OS-000040-GPOS-00018,SRG-OS-000041-GPOS-00019,SRG-OS-000042-GPOS-00021,SRG-OS-000051-GPOS-00024,SRG-OS-000054-GPOS-00025,SRG-OS-000122-GPOS-00063,SRG-OS-000254-GPOS-00095,SRG-OS-000255-GPOS-00096,SRG-OS-000337-GPOS-00129,SRG-OS-000348-GPOS-00136,SRG-OS-000349-GPOS-00137,SRG-OS-000350-GPOS-00138,SRG-OS-000351-GPOS-00139,SRG-OS-000352-GPOS-00140,SRG-OS-000353-GPOS-00141,SRG-OS-000354-GPOS-00142,SRG-OS-000358-GPOS-00145,SRG-OS-000365-GPOS-00152,SRG-OS-000392-GPOS-00172,SRG-OS-000475-GPOS-00220,SRG-APP-000095-CTR-000170,SRG-APP-000409-CTR-000990,SRG-APP-000508-CTR-001300,SRG-APP-000510-CTR-001310 | CCE-90829-3 | The operating system must provide an audit reduction capability that supports after-the-fact investigations of security incidents. | Red Hat Enterprise Linux 9 audit service must be enabled. | If the audit reduction capability does not support after-the-fact investigations, it is difficult to establish, correlate, and investigate the events leading up to an outage or attack or identify those responses for one. This capability is also required to comply with applicable Federal laws and DoD policies. Audit reduction capability must support after-the-fact investigations of security incidents either natively or through the use of third-party tools. This requirement is specific to operating systems with audit reduction capabilities. |
Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the "auditd" service is active ensures audit records generated by the kernel are appropriately recorded. Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions. |
Applicable - Configurable | Verify the operating system provides an audit reduction capability that supports after-the-fact investigations of security incidents. If it does not, this is a finding. | Verify the audit service is configured to produce audit records with the following command: $ systemctl status auditd.service auditd.service - Security Auditing Service Loaded:loaded (/usr/lib/systemd/system/auditd.service; enabled; vendor preset: enabled) Active: active (running) since Tues 2022-05-24 12:56:56 EST; 4 weeks 0 days ago If the audit service is not "active" and "running", this is a finding. |
To enable the auditd service run the following command: $ sudo systemctl enable --now auditd |
CAT III | |||||
| 8 | CCI-000133,CCI-001881,CCI-001875,CCI-000154,CCI-001882,CCI-000158,CCI-001914,CCI-000169,CCI-001464,CCI-001878,CCI-001877,CCI-001889,CCI-000135,CCI-002884,CCI-001487,CCI-003938,CCI-000132,CCI-000134,CCI-000172,CCI-000130,CCI-000131,CCI-001879,CCI-001880,CCI-001876,CCI-000159 | SRG-OS-000062-GPOS-00031,SRG-OS-000037-GPOS-00015,SRG-OS-000038-GPOS-00016,SRG-OS-000039-GPOS-00017,SRG-OS-000040-GPOS-00018,SRG-OS-000041-GPOS-00019,SRG-OS-000042-GPOS-00021,SRG-OS-000051-GPOS-00024,SRG-OS-000054-GPOS-00025,SRG-OS-000122-GPOS-00063,SRG-OS-000254-GPOS-00095,SRG-OS-000255-GPOS-00096,SRG-OS-000337-GPOS-00129,SRG-OS-000348-GPOS-00136,SRG-OS-000349-GPOS-00137,SRG-OS-000350-GPOS-00138,SRG-OS-000351-GPOS-00139,SRG-OS-000352-GPOS-00140,SRG-OS-000353-GPOS-00141,SRG-OS-000354-GPOS-00142,SRG-OS-000358-GPOS-00145,SRG-OS-000365-GPOS-00152,SRG-OS-000392-GPOS-00172,SRG-OS-000475-GPOS-00220 | CCE-83649-4 | The operating system must provide an audit reduction capability that supports after-the-fact investigations of security incidents. | Red Hat Enterprise Linux 9 audit package must be installed. | If the audit reduction capability does not support after-the-fact investigations, it is difficult to establish, correlate, and investigate the events leading up to an outage or attack or identify those responses for one. This capability is also required to comply with applicable Federal laws and DoD policies. Audit reduction capability must support after-the-fact investigations of security incidents either natively or through the use of third-party tools. This requirement is specific to operating systems with audit reduction capabilities. |
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured Red Hat Enterprise Linux 9 system. |
Applicable - Configurable | Verify the operating system provides an audit reduction capability that supports after-the-fact investigations of security incidents. If it does not, this is a finding. | Verify that the Red Hat Enterprise Linux 9 audit service package is installed. Check that the audit service package is installed with the following command: $ sudo dnf list --installed audit Example output: audit-3.0.7-101.el9_0.2.x86_64 If the "audit" package is not installed, this is a finding. |
Install the audit service package (if the audit service is not already installed) with the following command: $ sudo dnf install audit |
CAT III | |||||
| 9 | CCI-002322 | SRG-OS-000298-GPOS-00116 | The operating system must provide the capability to immediately disconnect or disable remote access to the operating system. | Red Hat Enterprise Linux 9 must provide the capability to immediately disconnect or disable remote access to the operating system. | Without the ability to immediately disconnect or disable remote access, an attack or other compromise taking place would not be immediately stopped. Operating system remote access functionality must have the capability to immediately disconnect current users remotely accessing the information system and/or disable further remote access. The speed of disconnect or disablement varies based on the criticality of missions functions and the need to eliminate immediate or future remote access to organizational information systems. The remote access functionality (e.g., RDP) may implement features such as automatic disconnect (or user-initiated disconnect) in case of adverse information based on an indicator of compromise or attack. |
Without the ability to immediately disconnect or disable remote access, an attack or other compromise taking place would not be immediately stopped. Red Hat Enterprise Linux 9 remote access functionality must have the capability to immediately disconnect current users remotely accessing the information system and/or disable further remote access. The speed of disconnect or disablement varies based on the criticality of missions functions and the need to eliminate immediate or future remote access to organizational information systems. The remote access functionality (e.g., RDP) may implement features such as automatic disconnect (or user-initiated disconnect) in case of adverse information based on an indicator of compromise or attack. |
Applicable - Inherently Met | Verify the operating system provides the capability to immediately disconnect or disable remote access to the operating system. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | The admin can shutdown networking to the host by port, NIC, or the entire network as desired. | The use of the "exit" command will end any communication session on the system. This is part of the kernel and cannot be removed without recompiling. The admin can shutdown networking to the host by port, NIC, or the entire network as desired. |
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| 10 | CCI-000171 | SRG-OS-000063-GPOS-00032 | CCE-89284-4 | The operating system must allow only the ISSM (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. | Red Hat Enterprise Linux 9 /etc/audit/auditd.conf file must have 0640 or less permissive to prevent unauthorized access. | Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Applicable - Configurable | Verify the operating system allows only the ISSM (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. If it does not, this is a finding. | Verify the mode of /etc/audit/auditd.conf with the command: $ sudo stat -c "%a %n" /etc/audit/auditd.conf 640 /etc/audit/auditd.conf If "/etc/audit/auditd.conf" does not have a mode of "0640", this is a finding. |
Set the mode of /etc/audit/auditd.conf file to 0640 with the command: $ sudo chmod 0640 /etc/audit/auditd.conf |
CAT II | |||||
| 11 | CCI-000171 | SRG-OS-000063-GPOS-00032 | CCE-89977-3 | The operating system must allow only the ISSM (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. | Red Hat Enterprise Linux 9 must allow only the information system security manager (ISSM) (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. | Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Applicable - Configurable | Verify the operating system allows only the ISSM (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. If it does not, this is a finding. | Verify that the files in directory "/etc/audit/rules.d/" and "/etc/audit/auditd.conf" file have a mode of "0640" or less permissive with the following command: # stat -c "%a %n" /etc/audit/rules.d/*.rules 640 /etc/audit/rules.d/audit.rules If the files in the "/etc/audit/rules.d/" directory or the "/etc/audit/auditd.conf" file have a mode more permissive than "0640", this is a finding. |
Configure the files in directory "/etc/audit/rules.d/" and the "/etc/audit/auditd.conf" file to have a mode of "0640" with the following commands: $ sudo chmod 0640 /etc/audit/rules.d/audit.rules $ sudo chmod 0640 /etc/audit/rules.d/[customrulesfile].rules $ sudo chmod 0640 /etc/audit/auditd.conf |
CAT II | |||||
| 12 | CCI-000172 | SRG-OS-000472-GPOS-00217 | The operating system must generate audit records showing starting and ending time for user access to the system. | Red Hat Enterprise Linux 9 must generate audit records showing starting and ending time for user access to the system. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Applicable - Inherently Met | Verify the operating system generates audit records showing starting and ending time for user access to the system. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
The technology inherently meets this requirement. No fix is required | CAT II | Linux kernel audit subsystem always adds a timestamp to each audit buffer used to contain the entire audit log data. Function kernel/audit.c:audit_log_start() calls kernel/audit.c:audit_get_stamp() to fetch the timestamp and formats the message into the audit log buffer. | Date/time stamps in the audit log are a function of the audit subsystem and cannot be modified or removed short of recompiling the audit packages. | ||||
| 13 | CCI-001941 | SRG-OS-000112-GPOS-00057 | The operating system must implement replay-resistant authentication mechanisms for network access to privileged accounts. | Red Hat Enterprise Linux 9 must implement replay-resistant authentication mechanisms for network access to privileged accounts. | A replay attack may enable an unauthorized user to gain access to the operating system. Authentication sessions between the authenticator and the operating system validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. A privileged account is any information system account with authorizations of a privileged user. Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. |
A replay attack may enable an unauthorized user to gain access to Red Hat Enterprise Linux 9. Authentication sessions between the authenticator and Red Hat Enterprise Linux 9 validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. A privileged account is any information system account with authorizations of a privileged user. Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. |
Applicable - Inherently Met | Verify the operating system implements replay-resistant authentication mechanisms for network access to privileged accounts. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | The release notes of OpenSSH 7.6 states "OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support." https://www.openssh.com/txt/release-7.6 |
The OpenSSH package in Red Hat Enterprise Linux 9 is version 9.6, which is newer than 7.6 which only supports SSH protocol 2.0 which is restraint to replay attacks. | ||||
| 14 | CCI-000044,CCI-002238 | SRG-OS-000329-GPOS-00128,SRG-OS-000021-GPOS-00005 | CCE-83587-6 | The operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes occur. | Red Hat Enterprise Linux 9 must automatically lock an account when three unsuccessful logon attempts occur. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | Applicable - Configurable | Verify the operating system automatically locks an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to lock an account after three unsuccessful logon attempts with the command: $ grep 'deny =' /etc/security/faillock.conf deny = 3 If the "deny" option is not set to "3" or less (but not "0"), is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to lock an account when three unsuccessful logon attempts occur. Add/Modify the "/etc/security/faillock.conf" file to match the following line: deny = 3 |
CAT II | |||||
| 15 | CCI-000044,CCI-002238 | SRG-OS-000329-GPOS-00128,SRG-OS-000021-GPOS-00005 | CCE-83589-2 | The operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes occur. | Red Hat Enterprise Linux 9 must automatically lock the root account until the root account is released by an administrator when three unsuccessful logon attempts occur during a 15-minute time period. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking the account. | Applicable - Configurable | Verify the operating system automatically locks an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to lock the root account after three unsuccessful logon attempts with the command: $ grep even_deny_root /etc/security/faillock.conf even_deny_root If the "even_deny_root" option is not set, is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to lock out the "root" account after a number of incorrect login attempts using "pam_faillock.so", first enable the feature using the following command: $ sudo authselect enable-feature with-faillock Then edit the "/etc/security/faillock.conf" file as follows: add or uncomment the following line: even_deny_root |
CAT II | |||||
| 16 | CCI-000044,CCI-002238 | SRG-OS-000329-GPOS-00128,SRG-OS-000021-GPOS-00005 | CCE-83583-5 | The operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes occur. | Red Hat Enterprise Linux 9 must automatically lock an account when three unsuccessful logon attempts occur during a 15-minute time period. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. | By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. |
Applicable - Configurable | Verify the operating system automatically locks an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 locks an account after three unsuccessful logon attempts within a period of 15 minutes with the following command: Note: If the System Administrator demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful logon attempts within a period of 15 minutes, this requirement is not applicable. $ grep fail_interval /etc/security/faillock.conf fail_interval = 900 If the "fail_interval" option is not set to "900" or less (but not "0"), the line is commented out, or the line is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to lock out the "root" account after a number of incorrect login attempts within 15 minutes using "pam_faillock.so", first enable the feature using the following command: $ authselect enable-feature with-faillock Then edit the "/etc/security/faillock.conf" file as follows: fail_interval = 900 |
CAT II | |||||
| 17 | CCI-000044,CCI-002238 | SRG-OS-000329-GPOS-00128,SRG-OS-000021-GPOS-00005 | CCE-83588-4 | The operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes occur. | Red Hat Enterprise Linux 9 must maintain an account lock until the locked account is released by an administrator. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. | By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. |
Applicable - Configurable | Verify the operating system automatically locks an account until the locked account is released by an administrator when three unsuccessful logon attempts in 15 minutes are made. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to lock an account until released by an administrator after three unsuccessful logon attempts with the command: $ grep 'unlock_time =' /etc/security/faillock.conf unlock_time = 0 If the "unlock_time" option is not set to "0", the line is missing, or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to lock an account until released by an administrator after three unsuccessful logon attempts with the command: $ authselect enable-feature with-faillock Then edit the "/etc/security/faillock.conf" file as follows: unlock_time = 0 |
CAT II | |||||
| 18 | CCI-000068 | SRG-OS-000033-GPOS-00014 | CCE-83446-5 | The operating system must implement DoD-approved encryption to protect the confidentiality of remote access sessions. | Red Hat Enterprise Linux 9 IP tunnels must use FIPS 140-2/140-3 approved cryptographic algorithms. | Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. |
Overriding the system crypto policy makes the behavior of the Libreswan service violate expectations, and makes system configuration more fragmented. | Applicable - Configurable | Verify the operating system implements DoD-approved encryption to protect the confidentiality of remote access sessions. If it does not, this is a finding. | Verify that the IPsec service uses the system crypto policy with the following command: Note: If the ipsec service is not installed, this requirement is Not Applicable. $ sudo grep include /etc/ipsec.conf /etc/ipsec.d/*.conf /etc/ipsec.conf:include /etc/crypto-policies/back-ends/libreswan.config If the ipsec configuration file does not contain "include /etc/crypto-policies/back-ends/libreswan.config", this is a finding. |
Configure Libreswan to use the system cryptographic policy. Add the following line to "/etc/ipsec.conf": include /etc/crypto-policies/back-ends/libreswan.config |
CAT I | |||||
| 19 | CCI-002421,CCI-000068,CCI-002418 | SRG-OS-000480-GPOS-00227,SRG-OS-000033-GPOS-00014 | CCE-90815-2 | The operating system must implement DoD-approved encryption to protect the confidentiality of remote access sessions. | Red Hat Enterprise Linux 9 Must Implement Dod-Approved Encryption To Protect The Confidentiality Of Remote Access Sessions. | Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. |
By decreasing the limit based on the amount of data and enabling time-based limit, effects of potential attacks against encryption keys are limited. |
Applicable - Configurable | Verify the operating system implements DoD-approved encryption to protect the confidentiality of remote access sessions. If it does not, this is a finding. | To check if RekeyLimit is set correctly, run the following command: $ sudo grep RekeyLimit /etc/ssh/sshd_config /etc/ssh/sshd_config.d/* If configured properly, output should be RekeyLimit 1G 1h If it is commented out or is not set, then this is a finding. |
Configure Red Hat Enterprise Linux 9 to force a frequent session key renegotiation for SSH connections to the server by adding or modifying the following line in the "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" file: RekeyLimit 1G 1h Restart the SSH daemon for the settings to take effect. $ sudo systemctl restart sshd.service |
CAT I | |||||
| 20 | CCI-002450,CCI-000068,CCI-002418,CCI-000877 | SRG-OS-000033-GPOS-00014,SRG-OS-000125-GPOS-00065,SRG-OS-000250-GPOS-00093,SRG-OS-000393-GPOS-00173,SRG-OS-000394-GPOS-00174,SRG-OS-000396-GPOS-00176,SRG-OS-000423-GPOS-00187,SRG-OS-000478-GPOS-00223 | CCE-83441-6 | The operating system must implement DoD-approved encryption to protect the confidentiality of remote access sessions. | Red Hat Enterprise Linux 9 must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. |
Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. |
Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. |
Applicable - Configurable | Verify the operating system implements DoD-approved encryption to protect the confidentiality of remote access sessions. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is in FIPS mode with the following command: $ sudo fips-mode-setup --check FIPS mode is enabled. If FIPS mode is not enabled, this is a finding. |
Configure the operating system to implement FIPS mode with the following command $ sudo fips-mode-setup --enable Reboot the system for the changes to take effect. |
CAT I | |||||
| 21 | CCI-003628,CCI-003627 | SRG-OS-000118-GPOS-00060 | CCE-83627-0 | The operating system must disable account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity. | Red Hat Enterprise Linux 9 Must Disable Account Identifiers (Individuals, Groups, Roles, And Devices) After 35 Days Of Inactivity. | Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. Operating systems need to track periods of inactivity and disable application identifiers after 35 days of inactivity. |
Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. |
Applicable - Configurable | Verify the operating system disables account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 account identifiers (individuals, groups, roles, and devices) are disabled after 35 days of inactivity with the following command: Check the account inactivity value by performing the following command: $ sudo grep -i inactive /etc/default/useradd INACTIVE=35 If "INACTIVE" is set to "-1", a value greater than "35", or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable account identifiers after 35 days of inactivity after the password expiration. Run the following command to change the configuration for useradd: $ sudo useradd -D -f 35 A recommendation is 35 days, but a lower value is acceptable. |
CAT II | |||||
| 22 | CCI-000050 | SRG-OS-000024-GPOS-00007 | The operating system must display the Standard Mandatory DoD Notice and Consent Banner until users acknowledge the usage conditions and take explicit actions to log on for further access. | Red Hat Enterprise Linux 9 must display the Standard Mandatory DoD Notice and Consent Banner until users acknowledge the usage conditions and take explicit actions to log on for further access. | The banner must be acknowledged by the user prior to allowing the user access to the operating system. This provides assurance that the user has seen the message and accepted the conditions for access. If the consent banner is not acknowledged by the user, DoD will not be in compliance with system use notifications required by law. To establish acceptance of the application usage policy, a click-through banner at system logon is required. The system must prevent further activity until the user executes a positive action to manifest agreement by clicking on a box indicating "OK". |
The banner must be acknowledged by the user prior to allowing the user access to the operating system. This provides assurance that the user has seen the message and accepted the conditions for access. If the consent banner is not acknowledged by the user, DoD will not be in compliance with system use notifications required by law. To establish acceptance of the application usage policy, a click-through banner at system logon is required. The system must prevent further activity until the user executes a positive action to manifest agreement by clicking on a box indicating "OK". |
Applicable - Does Not Meet | Verify the operating system displays the Standard Mandatory DoD Notice and Consent Banner until users acknowledge the usage conditions and take explicit actions to log on for further access. If it does not, this is a finding. | This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. |
CAT II | Ensure that the banner is prior to entering the user password to act as the "OK". Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
Red Hat Enterprise Linux 9 does not natively support a method of presenting an interactive acknowledgement of the login banner. | |||||
| 23 | CCI-000068,CCI-003123,CCI-002450,CCI-000877,CCI-002418,CCI-001453,CCI-002890 | SRG-OS-000396-GPOS-00176,SRG-OS-000393-GPOS-00173,SRG-OS-000394-GPOS-00174 | CCE-83450-7 | The operating system must implement NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Red Hat Enterprise Linux 9 must implement a system-wide encryption policy. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. | Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. | Applicable - Configurable | Verify the operating system implements NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. If it does not, this is a finding. | Verify that the Red Hat Enterprise Linux 9 cryptography policy has been configured correctly with the following commands: $ sudo update-crypto-policies --show FIPS If the cryptography is not set to "FIPS" and is not applied, this is a finding. $ sudo update-crypto-policies --check The configured policy matches the generated policy If the command does not return "The configured policy matches the generated policy", this is a finding. |
Configure the operating system to implement FIPS mode with the following command $ sudo fips-mode-setup --enable Reboot the system for the changes to take effect. |
CAT I | |||||
| 24 | CCI-002890,CCI-002450,CCI-003123 | SRG-OS-000396-GPOS-00176,SRG-OS-000393-GPOS-00173,SRG-OS-000394-GPOS-00174 | CCE-83442-4 | The operating system must implement NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Red Hat Enterprise Linux 9 must have the crypto-policies package installed. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. | Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. | Applicable - Configurable | Verify the operating system implements NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 crypto-policies package is installed with the following command: $ sudo dnf list --installed crypto-policies Example output: crypto-policies.noarch 20220223-1.git5203b41.el9_0.1 If the "crypto-policies" package is not installed, this is a finding. |
Install the crypto-policies package (if the package is not already installed) with the following command: $ sudo dnf install crypto-policies |
CAT I | |||||
| 25 | CCI-002450,CCI-000068,CCI-002418,CCI-000877 | SRG-OS-000478-GPOS-00223,SRG-OS-000396-GPOS-00176 | CCE-88742-2 | The operating system must implement NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Red Hat Enterprise Linux 9 must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect data requiring data-at-rest protections in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. |
Applicable - Configurable | Verify the operating system implements NSA-approved cryptography to protect classified information in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is in FIPS mode with the following command: $ fips-mode-setup --check FIPS mode is enabled. If FIPS mode is not enabled, this is a finding. |
Configure Red Hat Enterprise Linux 9 to run in FIPS mode with the following command: $ sudo fips-mode-setup --enable The system needs to be rebooted for these changes to take effect. |
CAT I | |||||
| 26 | CCI-002233,CCI-002234 | SRG-OS-000326-GPOS-00126,SRG-OS-000327-GPOS-00127,SRG-APP-000343-CTR-000780,SRG-APP-000381-CTR-000905,SRG-OS-000755-GPOS-00220 | CCE-86402-5 | The operating system must prevent all software from executing at higher privilege levels than users executing the software. | Red Hat Enterprise Linux 9 must audit uses of the "execve" system call. | In certain situations, software applications/programs need to execute with elevated privileges to perform required functions. However, if the privileges required for execution are at a higher level than the privileges assigned to organizational users invoking such applications/programs, those users are indirectly provided with greater privileges than assigned by the organizations. Some programs and processes are required to operate at a higher privilege level and therefore should be excluded from the organization-defined software list after review. |
Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. | Applicable - Configurable | Verify that the operating system prevents all software from executing at higher privilege levels than users executing the software. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "execve" system call with the following command: $ sudo auditctl -l | grep execve -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k execpriv If the command does not return all lines, or the lines are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to audit the execution of the "execve" system call. Add or update the following file system rules to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k execpriv The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 27 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000064-GPOS-0003,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-OS-000755-GPOS-00220 | CCE-83771-6 | The operating system must monitor the use of maintenance tools that execute with increased privilege. | Red Hat Enterprise Linux 9 must audit all uses of the su command. | Maintenance tools that execute with increased system privilege can result in unauthorized access to organizational information and assets that would otherwise be inaccessible. | Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system is configured to monitor the use of maintenance tools that execute with increased privilege. If the operating system is not configured to monitor the use of maintenance tools that execute with increased privilege, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "su" command with the following command: $ sudo auditctl -l | grep /usr/bin/su -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -k privileged-priv_change If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "su" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -k privileged-priv_change The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 28 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-OS-000755-GPOS-00220 | CCE-83780-7 | The operating system must monitor the use of maintenance tools that execute with increased privilege. | Red Hat Enterprise Linux 9 must audit all uses of the sudo command. | Maintenance tools that execute with increased system privilege can result in unauthorized access to organizational information and assets that would otherwise be inaccessible. | Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system is configured to monitor the use of maintenance tools that execute with increased privilege. If the operating system is not configured to monitor the use of maintenance tools that execute with increased privilege, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "sudo" command with the following command: $ sudo auditctl -l | grep /usr/bin/sudo -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "sudo" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 29 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235,SRG-OS-000755-GPOS-00220 | CCE-83764-1 | The operating system must monitor the use of maintenance tools that execute with increased privilege. | Red Hat Enterprise Linux 9 must audit all uses of the sudoedit command. | Maintenance tools that execute with increased system privilege can result in unauthorized access to organizational information and assets that would otherwise be inaccessible. | Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system is configured to monitor the use of maintenance tools that execute with increased privilege. If the operating system is not configured to monitor the use of maintenance tools that execute with increased privilege, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "sudoedit" command with the following command: $ sudo auditctl -l | grep /usr/bin/sudoedit -a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "sudoedit" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 30 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84177-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 cron configuration file directory must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/cron.d" directory with the following command: $ ls -lLd /etc/cron.d drwxr-xr-x. 2 root root 4096 July 11 11:34 /etc/cron.d If the "/etc/cron.d" directory does not have a group owner of "root", then this is a finding. |
Configure "/etc/cron.d" to be group-owned by root with the following command: $ sudo chgrp root /etc/cron.d |
CAT II | |||||
| 31 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84170-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 cron configuration files directory must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of all cron configuration files with the following command: $ stat -c "%G %n" /etc/cron* root /etc/cron.d root /etc/cron.daily root /etc/cron.deny root /etc/cron.hourly root /etc/cron.monthly root /etc/crontab root /etc/cron.weekly If any crontab is not group owned by root, this is a finding. |
Configure any cron configuration not group-owned by root with the following command: $ sudo chgrp root [cron config file] |
CAT II | |||||
| 32 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84186-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 cron configuration files directory must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of all cron configuration files with the command: $ stat -c "%U %n" /etc/cron* root /etc/cron.d root /etc/cron.daily root /etc/cron.deny root /etc/cron.hourly root /etc/cron.monthly root /etc/crontab root /etc/cron.weekly If any crontab is not owned by root, this is a finding. |
Configure any cron configuration not owned by root with the following command: $ sudo chown root [cron config file] |
CAT II | |||||
| 33 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84189-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the group ownership of /etc/cron.monthly , run the command: $ ls -lL /etc/cron.monthly If properly configured, the output should indicate the following group-owner: root If /etc/cron.monthly does not have a group owner of root, then this is a finding. |
CAT II | ||||||
| 34 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84174-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the group ownership of /etc/cron.weekly , run the command: $ ls -lL /etc/cron.weekly If properly configured, the output should indicate the following group-owner: root If /etc/cron.weekly does not have a group owner of root, then this is a finding. |
CAT II | ||||||
| 35 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84171-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the group ownership of /etc/crontab , run the command: $ ls -lL /etc/crontab If properly configured, the output should indicate the following group-owner: root If /etc/crontab does not have a group owner of root, then this is a finding. |
CAT II | ||||||
| 36 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83945-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/group" file with the following command: $ sudo stat -c "%G %n" /etc/group root /etc/group If "/etc/group" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/group to root by running the following command: $ sudo chgrp root /etc/group |
CAT II | |||||
| 37 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83948-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/gshadow" file with the following command: $ sudo stat -c "%G %n" /etc/gshadow root /etc/gshadow If "/etc/gshadow" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/gshadow to root by running the following command: $ sudo chgrp root /etc/gshadow |
CAT II | |||||
| 38 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83950-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/passwd" file contains information about the users that are configured on the system. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/passwd" file with the following command: $ sudo stat -c "%G %n" /etc/passwd root /etc/passwd If "/etc/passwd" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/passwd to root by running the following command: $ sudo chgrp root /etc/passwd |
CAT II | |||||
| 39 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83930-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow" file stores password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/shadow" file with the following command: $ sudo stat -c "%G %n" /etc/shadow root /etc/shadow If "/etc/shadow" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/shadow to root by running the following command: $ sudo chgrp root /etc/shadow |
CAT II | |||||
| 40 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83845-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /boot/grub2/grub.cfg file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The " /boot/grub2/grub.cfg" file stores sensitive system configuration. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/boot/grub2/grub.cfg" file with the following command: $ sudo stat -c "%U %n" /boot/grub2/grub.cfg root /boot/grub2/grub.cfg If "/boot/grub2/grub.cfg" file does not have an owner of "root", this is a finding. |
Change the owner of the file /boot/grub2/grub.cfg to root by running the following command: $ sudo chown root /boot/grub2/grub.cfg |
CAT II | |||||
| 41 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83848-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /boot/grub2/grub.cfg file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "root" group is a highly privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/boot/grub2/grub.cfg" file with the following command: $ sudo stat -c "%G %n" /boot/grub2/grub.cfg root /boot/grub2/grub.cfg If "/boot/grub2/grub.cfg" file does not have a group owner of "root", this is a finding. |
Change the group of the file /boot/grub2/grub.cfg to root by running the following command: $ sudo chgrp root /boot/grub2/grub.cfg |
CAT II | |||||
| 42 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84169-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.d , run the command: $ ls -lL /etc/cron.d If properly configured, the output should indicate the following owner: root If /etc/cron.d does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 43 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84188-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.daily , run the command: $ ls -lL /etc/cron.daily If properly configured, the output should indicate the following owner: root If /etc/cron.daily does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 44 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84168-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.hourly , run the command: $ ls -lL /etc/cron.hourly If properly configured, the output should indicate the following owner: root If /etc/cron.hourly does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 45 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84179-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.monthly , run the command: $ ls -lL /etc/cron.monthly If properly configured, the output should indicate the following owner: root If /etc/cron.monthly does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 46 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84190-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.weekly , run the command: $ ls -lL /etc/cron.weekly If properly configured, the output should indicate the following owner: root If /etc/cron.weekly does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 47 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83925-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/group" file with the following command: $ sudo stat -c "%U %n" /etc/group root /etc/group If "/etc/group" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/group to root by running the following command: $ sudo chown root /etc/group |
CAT II | |||||
| 48 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83924-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/gshadow" file with the following command: $ sudo stat -c "%U %n" /etc/gshadow root /etc/gshadow If "/etc/gshadow" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/gshadow to root by running the following command: $ sudo chown root /etc/gshadow |
CAT II | |||||
| 49 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83943-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/passwd" file contains information about the users that are configured on the system. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/passwd" file with the following command: $ sudo stat -c "%U %n" /etc/passwd root /etc/passwd If "/etc/passwd" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/passwd to root by running the following command: $ sudo chown root /etc/passwd |
CAT II | |||||
| 50 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83926-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/shadow" file with the following command: $ sudo stat -c "%U %n" /etc/shadow root /etc/shadow If "/etc/shadow" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/shadow to root by running the following command: $ sudo chown root /etc/shadow |
CAT II | |||||
| 51 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83928-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group- file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/group-" file with the following command: $ sudo stat -c "%G %n" /etc/group- root /etc/group- If "/etc/group-" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/group- to root by running the following command: $ sudo chgrp root /etc/group- |
CAT II | |||||
| 52 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83951-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow- file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/gshadow-" file with the following command: $ sudo stat -c "%G %n" /etc/gshadow- root /etc/gshadow- If "/etc/gshadow-" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/gshadow- to root by running the following command: $ sudo chgrp root /etc/gshadow- |
CAT II | |||||
| 53 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83933-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd- file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/passwd-" file with the following command: $ sudo stat -c "%G %n" /etc/passwd- root /etc/passwd- If "/etc/passwd-" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/passwd- to root by running the following command: $ sudo chgrp root /etc/passwd- |
CAT II | |||||
| 54 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83938-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow- file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/shadow-" file with the following command: $ sudo stat -c "%G %n" /etc/shadow- root /etc/shadow- If "/etc/shadow-" file does not have a group owner of "root", this is a finding. |
Change the group of the file /etc/shadow- to root by running the following command: $ sudo chgrp root /etc/shadow- |
CAT II | |||||
| 55 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83944-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group- file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/group-" file with the following command: $ sudo stat -c "%U %n" /etc/group- root /etc/group- If "/etc/group-" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/group- to root by running the following command: $ sudo chown root /etc/group- |
CAT II | |||||
| 56 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83929-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow- file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/gshadow-" file with the following command: $ sudo stat -c "%U %n" /etc/gshadow- root /etc/gshadow- If "/etc/gshadow-" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/gshadow- to root by running the following command: $ sudo chown root /etc/gshadow- |
CAT II | |||||
| 57 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83947-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd- file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/passwd-" file with the following command: $ sudo stat -c "%U %n" /etc/passwd- root /etc/passwd- If "/etc/passwd-" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/passwd- to root by running the following command: $ sudo chown root /etc/passwd- |
CAT II | |||||
| 58 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83949-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow- file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/shadow-" file with the following command: $ sudo stat -c "%U %n" /etc/shadow- root /etc/shadow- If "/etc/shadow-" file does not have an owner of "root", this is a finding. |
Change the owner of the file /etc/shadow- to root by running the following command: $ sudo chown root /etc/shadow- |
CAT II | |||||
| 59 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83939-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group- file must have mode 0644 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/group-" file has mode "0644" or less permissive with the following command: $ sudo stat -c "%a %n" /etc/group- 644 /etc/group- If a value of "0644" or less permissive is not returned, this is a finding. |
Change the mode of the file "/etc/group-" to "0644" by running the following command: $ sudo chmod 0644 /etc/group- |
CAT II | |||||
| 60 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83942-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow- file must have mode 0000 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/gshadow-" file has mode "0000" with the following command: $ sudo stat -c "%a %n" /etc/gshadow- 0 /etc/gshadow- If a value of "0" is not returned, this is a finding. |
Change the mode of the file "/etc/gshadow-" to "0000" by running the following command: $ sudo chmod 0000 /etc/gshadow- |
CAT II | |||||
| 61 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83940-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd- file must have mode 0644 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/passwd-" file has mode "0644" or less permissive with the following command: $ sudo stat -c "%a %n" /etc/passwd- 644 /etc/passwd- If a value of "0644" or less permissive is not returned, this is a finding. |
Change the mode of the file "/etc/passwd-" to "0644" by running the following command: $ sudo chmod 0644 /etc/passwd- |
CAT II | |||||
| 62 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83935-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow- file must have mode 0000 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/shadow-" file has mode "0000" with the following command: $ sudo stat -c "%a %n" /etc/shadow- 0 /etc/shadow- If a value of "0" is not returned, this is a finding. |
Change the mode of the file "/etc/shadow-" to "0000" by running the following command: $ sudo chmod 0000 /etc/shadow- |
CAT II | |||||
| 63 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84167-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/crontab , run the command: $ ls -lL /etc/crontab If properly configured, the output should indicate the following owner: root If /etc/crontab does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 64 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83934-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/group file must have mode 0644 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/group" file contains information regarding groups that are configured on the system. Protection of this file is important for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/group" file has mode "0644" or less permissive with the following command: $ sudo stat -c "%a %n" /etc/group 644 /etc/group If a value of "0644" or less permissive is not returned, this is a finding. |
Change the mode of the file "/etc/group" to "0644" by running the following command: $ sudo chmod 0644 /etc/group |
CAT II | |||||
| 65 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83921-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/gshadow file must have mode 0000 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/gshadow" file contains group password hashes. Protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/gshadow" file has mode "0000" with the following command: $ sudo stat -c "%a %n" /etc/gshadow 0 /etc/gshadow If a value of "0" is not returned, this is a finding. |
Change the mode of the file "/etc/gshadow" to "0000" by running the following command: $ sudo chmod 0000 /etc/gshadow |
CAT II | |||||
| 66 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83931-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/passwd file must have mode 0644 or less permissive to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the "/etc/passwd" file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/passwd" file has mode "0644" or less permissive with the following command: $ sudo stat -c "%a %n" /etc/passwd 644 /etc/passwd If a value of "0644" or less permissive is not returned, this is a finding. |
Change the mode of the file "/etc/passwd" to "0644" by running the following command: $ sudo chmod 0644 /etc/passwd |
CAT II | |||||
| 67 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83941-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/shadow file must have mode 0000 to prevent unauthorized access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the "/etc/shadow" file has mode "0000" with the following command: $ sudo stat -c "%a %n" /etc/shadow 0 /etc/shadow If a value of "0" is not returned, this is a finding. |
Change the mode of the file "/etc/shadow" to "0000" by running the following command: $ sudo chmod 0000 /etc/shadow |
CAT II | |||||
| 68 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84183-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 cron configuration directories must have a mode of 0700 or less permissive | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the permissions of the cron directories with the following command: $ find /etc/cron* -type d | xargs stat -c "%a %n" 700 /etc/cron.d 700 /etc/cron.daily 700 /etc/cron.hourly 700 /etc/cron.monthly 700 /etc/cron.weekly If any cron configuration directory is more permissive than 700, this is a finding. |
Configure any Red Hat Enterprise Linux 9 cron configration directory with a mode more permissive than 0700 as follows: chmod 0700 [cron configuration directory] |
CAT II | |||||
| 69 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84175-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the permissions of /etc/cron.daily , run the command: $ ls -l /etc/cron.daily If properly configured, the output should indicate the following permissions: -rwx------ If /etc/cron.daily does not have unix mode -rwx------, then this is a finding. |
CAT II | ||||||
| 70 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84173-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the permissions of /etc/cron.hourly , run the command: $ ls -l /etc/cron.hourly If properly configured, the output should indicate the following permissions: -rwx------ If /etc/cron.hourly does not have unix mode -rwx------, then this is a finding. |
CAT II | ||||||
| 71 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84181-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the permissions of /etc/cron.monthly , run the command: $ ls -l /etc/cron.monthly If properly configured, the output should indicate the following permissions: -rwx------ If /etc/cron.monthly does not have unix mode -rwx------, then this is a finding. |
CAT II | ||||||
| 72 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84187-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the permissions of /etc/cron.weekly , run the command: $ ls -l /etc/cron.weekly If properly configured, the output should indicate the following permissions: -rwx------ If /etc/cron.weekly does not have unix mode -rwx------, then this is a finding. |
CAT II | ||||||
| 73 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84176-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 /etc/crontab file must have mode 0600. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must have the correct access rights to prevent unauthorized changes. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the permissions of /etc/crontab with the following command: $ stat -c "%a %n" /etc/crontab 0600 If /etc/crontab does not have a mode of "0600", this is a finding. |
Configure the Red Hat Enterprise Linux 9 file /etc/crontab with mode 600. $ sudo chmod 0600 /etc/crontab |
CAT II | |||||
| 74 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86877-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | CAT II | |||||||||
| 75 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86844-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the ownership of /etc/cron.allow , run the command: $ ls -lL /etc/cron.allow If properly configured, the output should indicate the following owner: root If /etc/cron.allow does not have an owner of root, then this is a finding. |
CAT II | ||||||
| 76 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86830-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 Must Be Configured In Accordance With The Security Configuration Settings Based On Dod Security Configuration Or Implementation Guidance, Including Stigs, Nsa Configuration Guides, Ctos, And Dtms. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | To check the group ownership of /etc/cron.allow , run the command: $ ls -lL /etc/cron.allow If properly configured, the output should indicate the following group-owner: root If /etc/cron.allow does not have a group owner of root, then this is a finding. |
CAT II | ||||||
| 77 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90817-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH server configuration file must be group-owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the group ownership of the "/etc/ssh/sshd_config" file with the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" file does not have a group owner of "root", this is a finding. |
Configure the "/etc/ssh/sshd_config" file to be group-owned by root with the following command: $ sudo chgrp root /etc/ssh/sshd_config |
CAT II | |||||
| 78 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90821-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH server configuration file must be owned by root. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the ownership of the "/etc/ssh/sshd_config" file with the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" file does not have an owner of "root", this is a finding. |
Configure the "/etc/ssh/sshd_config" file to be owned by root with the following command: $ sudo chown root /etc/ssh/sshd_config |
CAT II | |||||
| 79 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90818-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH server configuration file must have mode 0600 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the permissions of the "/etc/ssh/sshd_config" file with the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" permissions are not "0600", this is a finding. |
Configure the "/etc/ssh/sshd_config" permissions to be "0600" with the following command: $ sudo chmod 0600 /etc/ssh/sshd_config |
CAT II | |||||
| 80 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90820-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH private host key files must have mode 0640 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If an unauthorized user obtains the private SSH host key file, the host could be impersonated. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH private host key files have a mode of "0640" or less permissive with the following command: $ ls -l /etc/ssh/*_key 640 /etc/ssh/ssh_host_dsa_key 640 /etc/ssh/ssh_host_ecdsa_key 640 /etc/ssh/ssh_host_ed25519_key 640 /etc/ssh/ssh_host_rsa_key If any private host key file has a mode more permissive than "0640", this is a finding. |
Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: $ sudo chmod 0640 /etc/ssh/ssh_host*key Restart the SSH daemon for the changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 81 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90819-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH public host key files must have mode 0644 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If a public host key file is modified by an unauthorized user, the SSH service may be compromised. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH public host key files have a mode of "0644" or less permissive with the following command: Note: SSH public key files may be found in other directories on the system depending on the installation. $ sudo stat -c "%a %n" /etc/ssh/*.pub 644 /etc/ssh/ssh_host_dsa_key.pub 644 /etc/ssh/ssh_host_ecdsa_key.pub 644 /etc/ssh/ssh_host_ed25519_key.pub 644 /etc/ssh/ssh_host_rsa_key.pub If any key.pub file has a mode more permissive than "0644", this is a finding. |
Change the mode of public host key files under "/etc/ssh" to "0644" with the following command: $ sudo chmod 0644 /etc/ssh/*key.pub Restart the SSH daemon for the changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 82 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83629-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local interactive user home directories must be group-owned by the home directory owner's primary group. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the Group Identifier (GID) of a local interactive users home directory is not the same as the primary GID of the user, this would allow unauthorized access to the users files, and users that share the same group may not be able to access files that they legitimately should. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the assigned home directory of all local interactive users is group-owned by that user's primary GID with the following command: Note: This may miss local interactive users that have been assigned a privileged user identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. The returned directory "/home/wadea" is used as an example. $ sudo ls -ld $(awk -F: '($3>=1000)&&($7 !~ /nologin/){print $6}' /etc/passwd) drwxr-x--- 2 wadea admin 4096 Jun 5 12:41 wadea Check the user's primary group with the following command: $ sudo grep $(grep wadea /etc/passwd | awk -F: ‘{print $4}') /etc/group admin:x:250:wadea,jonesj,jacksons If the user home directory referenced in "/etc/passwd" is not group-owned by that user's primary GID, this is a finding. |
Change the group owner of a local interactive user's home directory to the group found in "/etc/passwd". To change the group owner of a local interactive user's home directory, use the following command: Note: The example will be for the user "wadea", who has a home directory of "/home/wadea", and has a primary group of users. $ sudo chgrp users /home/wadea |
CAT II | |||||
| 83 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83637-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local initialization files must have mode 0740 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that all local initialization files have a mode of "0740" or less permissive with the following command: Note: The example will be for the "wadea" user, who has a home directory of "/home/wadea". $ sudo ls -al /home/wadea/.[^.]* | more -rwxr-xr-x 1 wadea users 896 Mar 10 2011 .profile -rwxr-xr-x 1 wadea users 497 Jan 6 2007 .login -rwxr-xr-x 1 wadea users 886 Jan 6 2007 .something If any local initialization files have a mode more permissive than "0740", this is a finding. |
Set the mode of the local initialization files to "0740" with the following command: Note: The example will be for the wadea user, who has a home directory of "/home/wadea". $ sudo chmod 0740 /home/wadea/.<INIT_FILE> |
CAT II | |||||
| 84 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83634-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local interactive user home directories must have mode 0750 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the assigned home directory of all local interactive users has a mode of "0750" or less permissive with the following command: Note: This may miss interactive users that have been assigned a privileged user identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. $ sudo ls -ld $(awk -F: '($3>=1000)&&($7 !~ /nologin/){print $6}' /etc/passwd) drwxr-x--- 2 wadea admin 4096 Jun 5 12:41 wadea If home directories referenced in "/etc/passwd" do not have a mode of "0750" or less permissive, this is a finding. |
Change the mode of interactive user's home directories to "0750". To change the mode of a local interactive user's home directory, use the following command: Note: The example will be for the user "wadea". $ sudo chmod 0750 /home/wadea |
CAT II | |||||
| 85 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83906-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local files and directories must have a valid group owner. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify all local files and directories on Red Hat Enterprise Linux 9 have a valid group with the following command: $ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nogroup If any files on the system do not have an assigned group, this is a finding. |
Either remove all files and directories from Red Hat Enterprise Linux 9 that do not have a valid group, or assign a valid group to all files and directories on the system with the "chgrp" command: $ sudo chgrp <group> <file> |
CAT II | |||||
| 86 | CCI-000366,CCI-001090 | SRG-OS-000480-GPOS-00227,SRG-OS-000138-GPOS-00069 | CCE-83903-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 world-writable directories must be owned by root, sys, bin, or an application user. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If a world-writable directory is not owned by root, sys, bin, or an application user identifier (UID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that world writable directories are owned by root, a system account, or an application account with the following command. It will discover and print world-writable directories that are not owned by root. Run it once for each local partition [PART]: $ sudo find PART -xdev -type d -perm -0002 -uid +0 -print If there is output, this is a finding. |
Configure all public directories to be owned by root or a system account to prevent unauthorized and unintended information transferred via shared system resources. Set the owner of all public directories as root or a system account using the command, replace "[Public Directory]" with any directory path not owned by root or a system account: $ sudo chown root [Public Directory] |
CAT II | |||||
| 87 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83896-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local files and directories must have a valid owner. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unowned files and directories may be unintentionally inherited if a user is assigned the same user identifier "UID" as the UID of the unowned files. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify all local files and directories on Red Hat Enterprise Linux 9 have a valid owner with the following command: $ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nouser If any files on the system do not have an assigned owner, this is a finding. |
Either remove all files and directories from the system that do not have a valid user, or assign a valid user to all unowned files and directories on Red Hat Enterprise Linux 9 with the "chown" command: $ sudo chown <user> <file> |
CAT II | |||||
| 88 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86887-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | CAT II | |||||||||
| 89 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86537-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | CAT II | |||||||||
| 90 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87087-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local initialization files must have mode 0740 or less permissive. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that all local initialization files have a mode of "0740" or less permissive with the following command: Note: The example will be for the "wadea" user, who has a home directory of "/home/wadea". $ sudo ls -al /home/wadea/.[^.]* | more -rwxr-xr-x 1 wadea users 896 Mar 10 2011 .profile -rwxr-xr-x 1 wadea users 497 Jan 6 2007 .login -rwxr-xr-x 1 wadea users 886 Jan 6 2007 .something If any local initialization files have a mode more permissive than "0740", this is a finding. |
Set the mode of the local initialization files to "0740" with the following command: Note: The example will be for the wadea user, who has a home directory of "/home/wadea". $ sudo chmod 0740 /home/wadea/.<INIT_FILE> |
CAT II | |||||
| 91 | CCI-000366 | SRG-OS-000269-GPOS-00103,SRG-OS-000480-GPOS-00227 | CCE-84232-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The kdump service on Red Hat Enterprise Linux 9 must be disabled. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Kernel core dumps may contain the full contents of system memory at the time of the crash. Kernel core dumps consume a considerable amount of disk space and may result in denial of service by exhausting the available space on the target file system partition. Unless the system is used for kernel development or testing, there is little need to run the kdump service. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the kdump service is disabled in system boot configuration with the following command: $ systemctl is-enabled kdump disabled Verify that the kdump service is not active (i.e., not running) through current runtime configuration with the following command: $ systemctl is-active kdump inactive Verify that the kdump service is masked with the following command: $ sudo systemctl show kdump | grep "LoadState\|UnitFileState" LoadState=masked UnitFileState=masked If the "kdump" service is loaded or active, and is not masked, this is a finding. |
Disable and mask the kdump service on Red Hat Enterprise Linux 9. To disable the kdump service run the following command: $ sudo systemctl disable --now kdump To mask the kdump service run the following command: $ sudo systemctl mask --now kdump |
CAT II | |||||
| 92 | CCI-000366,CCI-002235 | SRG-OS-000324-GPOS-00125,SRG-OS-000480-GPOS-00227 | CCE-90724-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 debug-shell systemd service must be disabled. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The debug-shell requires no authentication and provides root privileges to anyone who has physical access to the machine. While this feature is disabled by default, masking it adds an additional layer of assurance that it will not be enabled via a dependency in systemd. This also prevents attackers with physical access from trivially bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to mask the debug-shell systemd service with the following command: $ sudo systemctl status debug-shell.service debug-shell.service Loaded: masked (Reason: Unit debug-shell.service is masked.) Active: inactive (dead) If the "debug-shell.service" is loaded and not masked, this is a finding. |
Configure Red Hat Enterprise Linux 9 to mask the debug-shell systemd service with the following command: $ sudo systemctl disable --now debug-shell.service $ sudo systemctl mask --now debug-shell.service |
CAT II | |||||
| 93 | CCI-000778,CCI-000366,CCI-001958 | SRG-OS-000114-GPOS-00059,SRG-OS-000378-GPOS-00163,SRG-OS-000480-GPOS-00227 | CCE-83850-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 file system automount function must be disabled unless required. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 file system automount function has been disabled with the following command: $ sudo systemctl is-enabled autofs masked If the returned value is not "masked", "disabled", "Failed to get unit file state for autofs.service for autofs", or "enabled", and is not documented as operational requirement with the information system security officer ISSO, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the ability to automount devices. The autofs service can be disabled with the following command: $ sudo systemctl mask --now autofs.service |
CAT II | |||||
| 94 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83974-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable acquiring, saving, and processing core dumps. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is not configured to acquire, save, or process core dumps with the following command: $ sudo systemctl status systemd-coredump.socket systemd-coredump.socket Loaded: masked (Reason: Unit systemd-coredump.socket is masked.) Active: inactive (dead) If the "systemd-coredump.socket" is loaded and not masked and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Configure the system to disable the systemd-coredump.socket with the following command: $ sudo systemctl mask --now systemd-coredump.socket Created symlink /etc/systemd/system/systemd-coredump.socket -> /dev/null Reload the daemon for this change to take effect. $ sudo systemctl daemon-reload |
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| 95 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83989-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The rsyslog service on Red Hat Enterprise Linux 9 must be active. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "rsyslog" service must be running to provide logging services, which are essential to system administration. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that "rsyslog" is active with the following command: $ systemctl is-active rsyslog active If the rsyslog service is not active, this is a finding. |
To enable the rsyslog service, run the following command: $ sudo systemctl enable --now rsyslog |
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| 96 | CCI-000382,CCI-000366,CCI-002314 | SRG-OS-000096-GPOS-00050,SRG-OS-000297-GPOS-00115,SRG-OS-000480-GPOS-00227,SRG-OS-000480-GPOS-00231,SRG-OS-000480-GPOS-00232 | CCE-90833-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The firewalld service on Red Hat Enterprise Linux 9 must be active. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Red Hat Enterprise Linux 9 functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that "firewalld" is active with the following command: $ systemctl is-active firewalld active If the firewalld service is not active, this is a finding. |
To enable the firewalld service run the following command: $ sudo systemctl enable --now firewalld |
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| 97 | CCI-000366,CCI-000197,CCI-000381 | SRG-OS-000074-GPOS-00042,SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-84159-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have a File Transfer Protocol (FTP) server package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The FTP service provides an unencrypted remote access that does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to log on using this service, the privileged user password could be compromised. SSH or other encrypted file transfer methods must be used in place of this service. Removing the "vsftpd" package decreases the risk of accidental activation. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 does not have a File Transfer Protocol (FTP) server package installed with the following command: $ sudo dnf list --installed | grep ftp If the "ftp" package is installed, this is a finding. |
The ftp package can be removed with the following command (using vsftpd as an example): $ sudo dnf remove vsftpd |
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| 98 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84154-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have a Trivial File Transfer Protocol (TFTP) server package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Removing the "tftp-server" package decreases the risk of the accidental (or intentional) activation of tftp services. If TFTP is required for operational support (such as transmission of router configurations), its use must be documented with the information systems security manager (ISSM), restricted to only authorized personnel, and have access control rules established. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 does not have a "tftp-server" package installed with the following command: $ sudo dnf list --installed | grep tftp-server If the "tftp-server" package is installed, this is a finding. |
The "tftp-server" package can be removed with the following command: $ sudo dnf remove tftp-server |
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| 99 | CCI-000366,CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-83516-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have the gssproxy package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore, may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations (e.g., key missions, functions). The gssproxy package is a proxy for GSS API credential handling and could expose secrets on some networks. It is not needed for normal function of the OS. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the gssproxy package is not installed with the following command: $ sudo dnf list --installed gssproxy Error: No matching Packages to list If the "gssproxy" package is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Remove the gssproxy package with the following command: $ sudo dnf remove gssproxy |
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| 100 | CCI-000366,CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-83519-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have the iprutils package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The iprutils package provides a suite of utilities to manage and configure SCSI devices supported by the ipr SCSI storage device driver. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the iprutils package is not installed with the following command: $ sudo dnf list --installed iprutils Error: No matching Packages to list If the "iprutils" package is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Remove the iprutils package with the following command: $ sudo dnf remove iprutils |
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| 101 | CCI-000366,CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-83521-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have the tuned package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The tuned package contains a daemon that tunes the system settings dynamically. It does so by monitoring the usage of several system components periodically. Based on that information, components will then be put into lower or higher power savings modes to adapt to the current usage. The tuned package is not needed for normal OS operations. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the tuned package is not installed with the following command: $ sudo dnf list --installed tuned Error: No matching Packages to list If the "tuned" package is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Remove the tuned package with the following command: $ sudo dnf remove tuned |
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| 102 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84104-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | A graphical display manager must not be installed on Red Hat Enterprise Linux 9 unless approved. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a graphical user interface is not installed with the following command: $ sudo dnf list --installed "xorg*common" Error: No matching Packages to list If the "x11-server-common" package is installed and the use of a graphical user interface has not been documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. |
Document the requirement for a graphical user interface with the ISSO or remove all xorg packages with the following command: Warning: If you are accessing the system through the graphical user interface, change to the multi-user.target with the following command: $ sudo systemctl isolate multi-user.target Warning: Removal of the graphical user interface will immediately render it useless. The following commands should not be run from a virtual terminal emulator in the graphical interface. $ sudo dnf remove "xorg*" $ sudo systemctl set-default multi-user.target |
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| 103 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90836-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the openssh-clients package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
This package includes utilities to make encrypted connections and transfer files securely to SSH servers. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the openssh-clients package installed with the following command: $ sudo dnf list --installed openssh-clients Example output: openssh-clients.x86_64 8.7p1-8.el9 If the "openssh-clients" package is not installed, this is a finding. |
The openssh-clients package can be installed with the following command: $ sudo dnf install openssh-clients |
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| 104 | CCI-000366,CCI-000803 | SRG-OS-000480-GPOS-00227,SRG-OS-000120-GPOS-00061 | CCE-84068-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 libreswan package must be installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Providing the ability for remote users or systems to initiate a secure VPN connection protects information when it is transmitted over a wide area network. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 libreswan service package is installed. Check that the libreswan service package is installed with the following command: $ sudo dnf list --installed libreswan Example output: libreswan.x86_64 4.6-3.el9 If the "libreswan" package is not installed, this is a finding. |
Install the libreswan service (if it is not already installed) with the following command: $ sudo dnf install libreswan |
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| 105 | CCI-000366,CCI-000803 | SRG-OS-000480-GPOS-00227,SRG-OS-000120-GPOS-00061 | CCE-83987-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the packages required for encrypting offloaded audit logs installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The rsyslog-gnutls package provides Transport Layer Security (TLS) support for the rsyslog daemon, which enables secure remote logging. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the rsyslog-gnutls package installed with the following command: $ sudo dnf list --installed rsyslog-gnutls Example output: rsyslog-gnutls.x86_64 8.2102.0-101.el9_0.1 If the "rsyslog-gnutls" package is not installed, this is a finding. |
The rsyslog-gnutls package can be installed with the following command: $ sudo dnf install rsyslog-gnutls |
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| 106 | CCI-000366,CCI-000154,CCI-001851 | SRG-OS-000479-GPOS-00224,SRG-OS-000051-GPOS-00024,SRG-OS-000480-GPOS-00227 | CCE-84063-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the rsyslog package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
rsyslogd is a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Couple this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS, and DTLS protocols), to create a method to securely encrypt and offload auditing. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the rsyslogd package installed with the following command: $ sudo dnf list --installed rsyslog Example output: rsyslog.x86_64 8.2102.0-101.el9_0.1 If the "rsyslogd" package is not installed, this is a finding. |
The rsyslogd package can be installed with the following command: $ sudo dnf install rsyslogd |
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| 107 | CCI-000382,CCI-000366,CCI-002314,CCI-002322 | SRG-OS-000096-GPOS-00050,SRG-OS-000297-GPOS-00115,SRG-OS-000298-GPOS-00116,SRG-OS-000480-GPOS-00227,SRG-OS-000480-GPOS-00232 | CCE-84021-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the firewalld package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
"Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Red Hat Enterprise Linux 9 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Run the following command to determine if the firewalld package is installed with the following command: $ sudo dnf list --installed firewalld Example output: firewalld.noarch 1.0.0-4.el9 If the "firewall" package is not installed, this is a finding. |
To install the "firewalld" package run the following command: $ sudo dnf install firewalld |
CAT II | |||||
| 108 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83494-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the gnutls-utils package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
GnuTLS is a secure communications library implementing the SSL, TLS and DTLS protocols and technologies around them. It provides a simple C language application programming interface (API) to access the secure communications protocols as well as APIs to parse and write X.509, PKCS #12, OpenPGP and other required structures. This package contains command line TLS client and server and certificate manipulation tools. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the gnutls-utils package installed with the following command: $ dnf list --installed gnutls-utils Example output: gnutls-utils.x86_64 3.7.3-9.el9 If the "gnutls-utils" package is not installed, this is a finding. |
The gnutls-utils package can be installed with the following command: $ sudo dnf install gnutls-utils |
CAT II | |||||
| 109 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-89706-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have the nss-tools package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Network Security Services (NSS) is a set of libraries designed to support cross-platform development of security-enabled client and server applications. Install the "nss-tools" package to install command-line tools to manipulate the NSS certificate and key database. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the nss-tools package installed with the following command: $ dnf list --installed nss-tools Example output: nss-tools.x86_64 3.71.0-7.el9 If the "nss-tools" package is not installed, this is a finding. |
The nss-tools package can be installed with the following command: $ sudo dnf install nss-tools |
CAT II | |||||
| 110 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84070-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 policycoreutils-python-utils package must be installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The policycoreutils-python-utils package is required to operate and manage an SELinux environment and its policies. It provides utilities such as semanage, audit2allow, audit2why, chcat, and sandbox. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 policycoreutils-python-utils service package is installed with the following command: $ sudo dnf list --installed policycoreutils-python-utils Example output: policycoreutils-python-utils.noarch 3.3-6.el9_0 If the "policycoreutils-python-utils" package is not installed, this is a finding. |
Install the policycoreutils-python-utils service package (if the policycoreutils-python-utils service is not already installed) with the following command: $ sudo dnf install policycoreutils-python-utils |
CAT II | |||||
| 111 | CCI-000366,CCI-001084 | SRG-OS-000480-GPOS-00227,SRG-OS-000134-GPOS-00068 | CCE-84071-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must have policycoreutils package installed. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. Policycoreutils contains the policy core utilities that are required for basic operation of an SELinux-enabled system. These utilities include load_policy to load SELinux policies, setfile to label filesystems, newrole to switch roles, and run_init to run /etc/init.d scripts in the proper context. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the policycoreutils package installed with the following command: $ sudo dnf list --installed policycoreutils Example output: policycoreutils.x86_64 3.3-6.el9_0 If the "policycoreutils" package is not installed, this is a finding. |
The policycoreutils package can be installed with the following command: $ sudo dnf install policycoreutils |
CAT II | |||||
| 112 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90838-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent special devices on file systems that are imported via Network File System (NFS). | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the "nodev" option configured for all NFS mounts with the following command: $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5:krb5i:krb5p Note: If no NFS mounts are configured, this requirement is Not Applicable. If the system is mounting file systems via NFS and the "nodev" option is missing, this is a finding. |
Update each NFS mounted file system to use the "nodev" option on file systems that are being imported via NFS. | CAT II | |||||
| 113 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84246-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent code from being executed on file systems that are imported via Network File System (NFS). | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "noexec" mount option causes the system not to execute binary files. This option must be used for mounting any file system not containing approved binary as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the "noexec" option configured for all NFS mounts with the following command: $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5:krb5i:krb5p If no NFS mounts are configured, this requirement is Not Applicable. If the system is mounting file systems via NFS and the "noexec" option is missing, this is a finding. |
Update each NFS mounted file system to use the "noexec" option on file systems that are being imported via NFS. | CAT II | |||||
| 114 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84247-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent files with the setuid and setgid bit set from being executed on file systems that are imported via Network File System (NFS). | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the "nosuid" option configured for all NFS mounts with the following command: Note: If no NFS mounts are configured, this requirement is Not Applicable. $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5:krb5i:krb5p If the system is mounting file systems via NFS and the "nosuid" option is missing, this is a finding. |
Update each NFS mounted file system to use the "nosuid" option on file systems that are being imported via NFS. | CAT II | |||||
| 115 | CCI-000366,CCI-001764 | SRG-OS-000368-GPOS-00154,SRG-OS-000480-GPOS-00227 | CCE-83877-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent files with the setuid and setgid bit set from being executed on the /boot directory. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Note: For systems that use UEFI, this requirement is Not Applicable. Verify the /boot directory is mounted with the "nosuid" option with the following command: $ mount | grep '\s/boot\s' /dev/sda1 on /boot type xfs (rw,nosuid,relatime,seclabe,attr2,inode64,noquota) If the /boot file system does not have the "nosuid" option set, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/boot" directory. | CAT II | |||||
| 116 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83875-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent code from being executed on file systems that contain user home directories. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify "/home" is mounted with the "noexec" option with the following command: Note: If a separate file system has not been created for the user home directories (user home directories are mounted under "/"), this is automatically a finding, as the "noexec" option cannot be used on the "/" system. $ mount | grep /home tmpfs on /home type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/home" file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/home" directory. | CAT II | |||||
| 117 | CCI-000366,CCI-001764 | SRG-OS-000368-GPOS-00154,SRG-OS-000480-GPOS-00227 | CCE-83894-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent files with the setuid and setgid bit set from being executed on file systems that contain user home directories. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify "/home" is mounted with the "nosuid" option with the following command: Note: If a separate file system has not been created for the user home directories (user home directories are mounted under "/"), this is automatically a finding, as the "nosuid" option cannot be used on the "/" system. $ mount | grep /home tmpfs on /home type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the "/home" file system is mounted without the "nosuid" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/home" directory. | CAT II | |||||
| 118 | CCI-000366 | SRG-OS-000368-GPOS-00154,SRG-OS-000480-GPOS-00227 | CCE-83873-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent special devices on non-root local partitions. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify all non-root local partitions are mounted with the "nodev" option with the following command: $ sudo mount | grep '^/dev\S* on /\S' | grep --invert-match 'nodev' If any output is produced, this is a finding. |
Configure the "/etc/fstab" to use the "nodev" option on all non-root local partitions. | CAT II | |||||
| 119 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83856-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent special devices on file systems that are used with removable media. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nodev" mount option causes the system not to interpret character or block special devices. Executing character or blocking special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify file systems that are used for removable media are mounted with the "nodev" option with the following command: $ more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "nodev" option set, this is a finding. |
Configure the "/etc/fstab" to use the "nodev" option on file systems that are associated with removable media. | CAT II | |||||
| 120 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83883-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent code from being executed on file systems that are used with removable media. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "noexec" mount option causes the system not to execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify file systems that are used for removable media are mounted with the "noexec" option with the following command: $ more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "noexec" option set, this is a finding. |
Configure the "/etc/fstab" to use the "noexec" option on file systems that are associated with removable media. | CAT II | |||||
| 121 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83874-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent files with the setuid and setgid bit set from being executed on file systems that are used with removable media. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify file systems that are used for removable media are mounted with the "nosuid" option with the following command: $ more /etc/fstab UUID=2bc871e4-e2a3-4f29-9ece-3be60c835222 /mnt/usbflash vfat noauto,owner,ro,nosuid,nodev,noexec 0 0 If a file system found in "/etc/fstab" refers to removable media and it does not have the "nosuid" option set, this is a finding. |
Configure the "/etc/fstab" to use the "nosuid" option on file systems that are associated with removable media. | CAT II | |||||
| 122 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87416-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
When an NFS server is configured to use RPCSEC_SYS, a selected userid and groupid are used to handle requests from the remote user. The userid and groupid could mistakenly or maliciously be set incorrectly. The RPCSEC_GSS method of authentication uses certificates on the server and client systems to more securely authenticate the remote mount request. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the "sec" option configured for all NFS mounts with the following command: Note: If no NFS mounts are configured, this requirement is Not Applicable. $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5p:krb5i:krb5 If the system is mounting file systems via NFS and has the sec option without the "krb5:krb5i:krb5p" settings, the "sec" option has the "sys" setting, or the "sec" option is missing, this is a finding. |
Update the "/etc/fstab" file so the option "sec" is defined for each NFS mounted file system and the "sec" option does not have the "sys" setting. Ensure the "sec" option is defined as "krb5p:krb5i:krb5". |
CAT II | |||||
| 123 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-89947-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
When an NFS server is configured to use AUTH_SYS a selected userid and groupid are used to handle requests from the remote user. The userid and groupid could mistakenly or maliciously be set incorrectly. The AUTH_GSS method of authentication uses certificates on the server and client systems to more securely authenticate the remote mount request. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 has the "sec" option is configured for all NFS exports with the following command: Note: If the system does not have any filesystems mounted for NFS export this requirement is Not Applicable. $ grep "sec=" /etc/exports 192.168.17.7:/mnt/export /data1 nfs4 rw,sync ,soft,sec=krb5p:krb5i:krb5 If the system is exporting file systems via NFS and has the sec option without the "krbp:krb5i:krb5" settings, the "sec" option has the "sys" setting, or the "sec" option is missing, this is a finding. |
Update the "/etc/fstab" file so the option "sec" is defined for each NFS mounted file system and the "sec" option does not have the "sys" setting. Ensure the "sec" option is defined as "krb5p:krb5i:krb5". |
CAT II | |||||
| 124 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90801-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The Red Hat Enterprise Linux 9 SSH daemon must not allow compression or must only allow compression after successful authentication. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon performs compression after a user successfully authenticates with the following command: $ sudo grep -ir compression /etc/ssh/sshd_config /etc/ssh/sshd_config.d/* Compression delayed If the "Compression" keyword is set to "yes", is missing, or the returned line is commented out, this is a finding. |
Configure the SSH daemon to not allow compression. Uncomment the "Compression" keyword in "/etc/ssh/sshd_config" on the system and set the value to "delayed" or "no": Compression no The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 125 | CCI-000766,CCI-000366 | SRG-OS-000106-GPOS-00053,SRG-OS-000480-GPOS-00229,SRG-OS-000480-GPOS-00227 | CCE-90799-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSHD must not allow blank passwords. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 remote access using SSH prevents logging on with a blank password with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*permitemptypasswords' PermitEmptyPassword no If the "PermitEmptyPassword" keyword is set to "yes", is missing, or is commented out, this is a finding. |
To configure the system to prevent SSH users from logging on with blank passwords edit the following line in "etc/ssh/sshd_config": PermitEmptyPasswords no Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 126 | CCI-000366,CCI-001813 | SRG-OS-000364-GPOS-00151,SRG-OS-000480-GPOS-00227 | CCE-90808-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must not allow GSSAPI authentication. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Generic Security Service Application Program Interface (GSSAPI) authentication is used to provide additional authentication mechanisms to applications. Allowing GSSAPI authentication through SSH exposes the system's GSSAPI to remote hosts, increasing the attack surface of the system. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon does not allow GSSAPI authentication with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*gssapiauthentication' GSSAPIAuthentication no If the value is returned as "yes", the returned line is commented out, no output is returned, and the use of GSSAPI authentication has not been documented with the information system security officer (ISSO), this is a finding. If the required value is not set, this is a finding. |
Configure the SSH daemon to not allow GSSAPI authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": GSSAPIAuthentication no The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 127 | CCI-000366,CCI-001813 | SRG-OS-000364-GPOS-00151,SRG-OS-000480-GPOS-00227 | CCE-90802-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must not allow Kerberos authentication. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Kerberos authentication for SSH is often implemented using Generic Security Service Application Program Interface (GSSAPI). If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon does not allow Kerberos authentication with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*kerberosauthentication' KerberosAuthentication no If the value is returned as "yes", the returned line is commented out, no output is returned, and the use of Kerberos authentication has not been documented with the information system security officer (ISSO), this is a finding. |
Configure the SSH daemon to not allow Kerberos authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": KerberosAuthentication no The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 128 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90797-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must not allow rhosts authentication. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon does not allow rhosts authentication with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*ignorerhosts' IgnoreRhosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding. |
Configure the SSH daemon to not allow rhosts authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": IgnoreRhosts yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 129 | CCI-000366,CCI-004045 | SRG-OS-000109-GPOS-00056,SRG-OS-000480-GPOS-00227,SRG-APP-000148-CTR-000335,SRG-APP-000190-CTR-000500 | CCE-90800-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not permit direct logons to the root account using remote access via SSH. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 remote access using SSH prevents users from logging on directly as "root" with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*permitrootlogin' PermitRootLogin no If the "PermitRootLogin" keyword is set to "yes", is missing, or is commented out, this is a finding. |
To configure the system to prevent SSH users from logging on directly as root add or modify the following line in "/etc/ssh/sshd_config". PermitRootLogin no Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 130 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90796-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must not allow known hosts authentication. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Configuring the IgnoreUserKnownHosts setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon does not allow known hosts authentication with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*ignoreuserknownhosts' IgnoreUserKnownHosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding. |
Configure the SSH daemon to not allow known hosts authentication. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": IgnoreUserKnownHosts yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 131 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90798-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must disable remote X connections for interactive users. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the DISPLAY environment variable to localhost. This prevents remote hosts from connecting to the proxy display. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon does not allow X11Forwarding with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*x11forwarding' X11forwarding no If the value is returned as "yes", the returned line is commented out, or no output is returned, and X11 forwarding is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Configure the SSH daemon to not allow X11 forwarding. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "no": X11forwarding no The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 132 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90809-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must perform strict mode checking of home directory configuration files. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon performs strict mode checking of home directory configuration files with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*strictmodes' StrictModes yes If the "StrictModes" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding. |
Configure the SSH daemon to perform strict mode checking of home directory configuration files. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": StrictModes yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 133 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90804-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must display the date and time of the last successful account logon upon an SSH logon. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Providing users feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon provides users with feedback on when account accesses last occurred with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*printlastlog' PrintLastLog yes If the "PrintLastLog" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding. |
Configure the SSH daemon to provide users with feedback on when account accesses last occurred. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": PrintLastLog yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 134 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-89105-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 SSH daemon must prevent remote hosts from connecting to the proxy display. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
When X11 forwarding is enabled, there may be additional exposure to the server and client displays if the sshd proxy display is configured to listen on the wildcard address. By default, sshd binds the forwarding server to the loopback address and sets the hostname part of the "DISPLAY" environment variable to localhost. This prevents remote hosts from connecting to the proxy display. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the SSH daemon prevents remote hosts from connecting to the proxy display with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*x11uselocalhost' X11UseLocalhost yes If the "X11UseLocalhost" keyword is set to "no", is missing, or is commented out, this is a finding. |
Configure the SSH daemon to prevent remote hosts from connecting to the proxy display. Add the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": X11UseLocalhost yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 135 | CCI-000366,CCI-000169 | SRG-OS-000062-GPOS-00031,SRG-OS-000480-GPOS-00227 | CCE-83682-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 audit system must audit local events. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. If option "local_events" isn't set to "yes" only events from network will be aggregated. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the Red Hat Enterprise Linux 9 audit system is configured to audit local events with the following command: $ sudo grep local_events /etc/audit/auditd.conf local_events = yes If "local_events" isn't set to "yes", if the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for local events by adding or updating the following line in "/etc/audit/auditd.conf": local_events = yes The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 136 | CCI-000366,CCI-001487 | SRG-OS-000255-GPOS-00096,SRG-OS-000480-GPOS-00227,SRG-APP-000096-CTR-000175,SRG-APP-000097-CTR-000180,SRG-APP-000098-CTR-000185,SRG-APP-000099-CTR-000190,SRG-APP-000100-CTR-000195,SRG-APP-000100-CTR-000200,SRG-APP-000109-CTR-000215,SRG-APP-000290-CTR-000670,SRG-APP-000357-CTR-000800 | CCE-83696-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must produce audit records containing information to establish the identity of any individual or process associated with the event. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Enriched logging aids in making sense of who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 audit system is configured to resolve audit information before writing to disk, with the following command: $ sudo grep log_format /etc/audit/auditd.conf log_format = ENRICHED If the "log_format" option is not "ENRICHED", or the line is commented out, this is a finding. |
Edit the /etc/audit/auditd.conf file and add or update the "log_format" option: log_format = ENRICHED The audit daemon must be restarted for changes to take effect. |
CAT II | |||||
| 137 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83705-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must write audit records to disk. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Audit data should be synchronously written to disk to ensure log integrity. This setting assures that all audit event data is written disk. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the audit system is configured to write logs to the disk with the following command: $ sudo grep write_logs /etc/audit/auditd.conf write_logs = yes If "write_logs" does not have a value of "yes", the line is commented out, or the line is missing, this is a finding. |
Configure the audit system to write log files to the disk. Edit the /etc/audit/auditd.conf file and add or update the "write_logs" option to "yes": write_logs = yes The audit daemon must be restarted for changes to take effect. |
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| 138 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84120-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not accept router advertisements on all IPv6 interfaces. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An illicit router advertisement message could result in a man-in-the-middle attack. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not accept router advertisements on all IPv6 interfaces, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Determine if router advertisements are not accepted by using the following command: $ sudo sysctl net.ipv6.conf.all.accept_ra net.ipv6.conf.all.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.all.accept_ra | tail -1 net.ipv6.conf.all.accept_ra = 0 If "net.ipv6.conf.all.accept_ra" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not accept router advertisements on all IPv6 interfaces unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_ra = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 139 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84125-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must ignore IPv6 Internet Control Message Protocol (ICMP) redirect messages. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An illicit ICMP redirect message could result in a man-in-the-middle attack. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 ignores IPv6 ICMP redirect messages. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the "accept_redirects" variables with the following command: $ sysctl net.ipv6.conf.all.accept_redirects net.ipv6.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.all.accept_redirects | tail -1 net.ipv6.conf.all.accept_redirects = 0 If "net.ipv6.conf.all.accept_redirects" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to ignore IPv6 ICMP redirect messages. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 140 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84131-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not forward IPv6 source-routed packets. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not accept IPv6 source-routed packets. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv6.conf.all.accept_source_route net.ipv6.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.all.accept_source_route | tail -1 net.ipv6.conf.all.accept_source_route = 0 If "net.ipv6.conf.all.accept_source_route" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not forward IPv6 source-routed packets. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_source_route = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 141 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84114-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not enable IPv6 packet forwarding unless the system is a router. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is not performing IPv6 packet forwarding, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check that IPv6 forwarding is disabled using the following commands: $ sudo sysctl net.ipv6.conf.all.forwarding net.ipv6.conf.all.forwarding = 0 If the IPv6 forwarding value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.all.forwarding | tail -1 net.ipv6.conf.all.forwarding = 0 If "net.ipv6.conf.all.forwarding" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow IPv6 packet forwarding, unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.forwarding = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 142 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84124-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not accept router advertisements on all IPv6 interfaces by default. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An illicit router advertisement message could result in a man-in-the-middle attack. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not accept router advertisements on all IPv6 interfaces by default, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Determine if router advertisements are not accepted by default by using the following command: $ sudo sysctl net.ipv6.conf.default.accept_ra net.ipv6.conf.default.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.default.accept_ra | tail -1 net.ipv6.conf.default.accept_ra = 0 If "net.ipv6.conf.default.accept_ra" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not accept router advertisements on all IPv6 interfaces by default unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_ra = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 143 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84113-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent IPv6 Internet Control Message Protocol (ICMP) redirect messages from being accepted. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 will not accept IPv6 ICMP redirect messages. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the default "accept_redirects" variables with the following command: $ sudo sysctl net.ipv6.conf.default.accept_redirects net.ipv6.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.default.accept_redirects | tail -1 net.ipv6.conf.default.accept_redirects = 0 If "net.ipv6.conf.default.accept_redirects" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent IPv6 ICMP redirect messages from being accepted. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 144 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84130-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not forward IPv6 source-routed packets by default. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It must be disabled unless it is absolutely required. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not accept IPv6 source-routed packets by default. Note: If IPv6 is disabled on the system, this requirement is Not Applicable. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv6.conf.default.accept_source_route net.ipv6.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv6.conf.default.accept_source_route | tail -1 net.ipv6.conf.default.accept_source_route = 0 If "net.ipv6.conf.default.accept_source_route" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not forward IPv6 source-routed packets by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_source_route = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 145 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84011-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must ignore Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 will not accept IPv4 ICMP redirect messages. Check the value of the all "accept_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.all.accept_redirects net.ipv4.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.all.accept_redirects | tail -1 net.ipv4.conf.all.accept_redirects = 0 If "net.ipv4.conf.all.accept_redirects" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to ignore IPv4 ICMP redirect messages. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.accept_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 146 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84001-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not forward Internet Protocol version 4 (IPv4) source-routed packets. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 will not accept IPv4 source-routed packets. Check the value of the all "accept_source_route" variables with the following command: $ sudo sysctl net.ipv4.conf.all.accept_source_route net.ipv4.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.all.accept_source_route | tail -1 net.ipv4.conf.all.accept_source_route = 0 If "net.ipv4.conf.all.accept_source_route" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to ignore IPv4 source-routed packets. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.accept_source_route = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 147 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87181-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not enable IPv4 packet forwarding unless the system is a router. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is not performing IPv4 packet forwarding, unless the system is a router. Check that IPv4 forwarding is disabled using the following command: $ sudo sysctl net.ipv4.conf.all.forwarding net.ipv4.conf.all.forwarding = 0 If the IPv4 forwarding value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo (/usr/lib/systemd/systemd-sysctl --cat-config; cat /etc/sysctl.conf) | egrep -v '^(#|$)' | grep net.ipv4.conf.all.forwarding | tail -1 net.ipv4.conf.all.forwarding = 0 If "net.ipv4.conf.all.forwarding" is not set to "0" and is not documented with the ISSO as an operational requirement or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow IPv4 packet forwarding, unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.forwarding = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 148 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84007-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not forward IPv4 source-routed packets by default. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not accept IPv4 source-routed packets by default. Check the value of the accept source route variable with the following command: $ sudo sysctl net.ipv4.conf.default.accept_source_route net.ipv4.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.default.accept_source_route | tail -1 net.ipv4.conf.default.accept_source_route = 0 If "net.ipv4.conf.default.accept_source_route" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not forward IPv4 source-routed packets by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.accept_source_route = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 149 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84008-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use reverse path filtering on all IPv4 interfaces. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks, but is helpful for end hosts and routers serving small networks. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 uses reverse path filtering on all IPv4 interfaces with the following commands: $ sudo sysctl net.ipv4.conf.all.rp_filter net.ipv4.conf.all.rp_filter = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.all.rp_filter | tail -1 net.ipv4.conf.all.rp_filter = 1 If "net.ipv4.conf.all.rp_filter" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use reverse path filtering on all IPv4 interfaces. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.rp_filter = 1 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
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| 150 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84009-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a reverse-path filter for IPv4 network traffic when possible by default. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks, but is helpful for end hosts and routers serving small networks. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 uses reverse path filtering on IPv4 interfaces with the following commands: $ sudo sysctl net.ipv4.conf.default.rp_filter net.ipv4.conf.default.rp_filter = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.default.rp_filter | tail -1 net.ipv4.conf.default.rp_filter = 1 If "net.ipv4.conf.default.rp_filter" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use reverse path filtering on IPv4 interfaces by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.rp_filter = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 151 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84004-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks. Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not respond to ICMP echoes sent to a broadcast address. Check the value of the "icmp_echo_ignore_broadcasts" variable with the following command: $ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts net.ipv4.icmp_echo_ignore_broadcasts = 1 If the returned line does not have a value of "1", a line is not returned, or the retuned line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|$)' | grep -F net.ipv4.icmp_echo_ignore_broadcasts | tail -1 net.ipv4.icmp_echo_ignore_broadcasts = 1 If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not respond to IPv4 ICMP echoes sent to a broadcast address. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.icmp_echo_ignore_broadcasts = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 152 | CCI-001095,CCI-000366,CCI-002385 | SRG-OS-000480-GPOS-00227,SRG-OS-000420-GPOS-00186,SRG-OS-000142-GPOS-00071 | CCE-84006-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured to use TCP syncookies. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Denial of service (DoS) is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to use IPv4 TCP syncookies. Determine if syncookies are used with the following command: Check the status of the kernel.perf_event_paranoid kernel parameter. $ sudo sysctl net.ipv4.tcp_syncookies net.ipv4.tcp_syncookies = 1 Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.tcp_syncookies | tail -1 net.ipv4.tcp_syncookies = 1 If the network parameter "ipv4.tcp_syncookies" is not equal to "1" or nothing is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use TCP syncookies. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: net.ipv4.tcp_syncookies = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 153 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83997-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not send Internet Control Message Protocol (ICMP) redirects. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not IPv4 ICMP redirect messages. Check the value of the "all send_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.all.send_redirects net.ipv4.conf.all.send_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.all.send_redirects | tail -1 net.ipv4.conf.all.send_redirects = 0 If "net.ipv4.conf.all.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow interfaces to perform IPv4 ICMP redirects. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.send_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 154 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84003-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent IPv4 Internet Control Message Protocol (ICMP) redirect messages from being accepted. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It must be disabled unless absolutely required. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 will not accept IPv4 ICMP redirect messages. Check the value of the default "accept_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.default.accept_redirects net.ipv4.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", a line is not returned, or the line is commented out, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.default.accept_redirects | tail -1 net.ipv4.conf.default.accept_redirects = 0 If "net.ipv4.conf.default.accept_redirects" is not set to "0" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent IPv4 ICMP redirect messages from being accepted. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.accept_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 155 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83999-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not allow interfaces to perform Internet Control Message Protocol (ICMP) redirects by default. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 does not allow interfaces to perform Internet Protocol version 4 (IPv4) ICMP redirects by default. Check the value of the "default send_redirects" variables with the following command: $ sudo sysctl net.ipv4.conf.default.send_redirects net.ipv4.conf.default.send_redirects=0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.default.send_redirects | tail -1 net.ipv4.conf.default.send_redirects = 0 If "net.ipv4.conf.default.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow interfaces to perform Internet Protocol version 4 (IPv4) ICMP redirects by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.send_redirects = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 156 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83998-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not enable IPv4 packet forwarding unless the system is a router. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is not performing IPv4 packet forwarding, unless the system is a router. Check that IPv4 forwarding is disabled using the following command: $ sysctl net.ipv4.conf.all.forwarding net.ipv4.conf.all.forwarding = 0 If the IPv4 forwarding value is not "0" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to enable this network parameter. $ { /usr/lib/systemd/systemd-sysctl --cat-config; cat /etc/sysctl.conf; } | grep -Ev '^(#|$)' | grep -F net.ipv4.conf.all.forwarding | tail -1 net.ipv4.conf.all.forwarding = 0 If "net.ipv4.conf.all.forwarding" is not set to "0" and is not documented with the Information System Security Officer (ISSO) as an operational requirement, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow IPv4 packet forwarding, unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.forwarding = 0 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 157 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84015-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must limit the number of bogus Internet Control Message Protocol (ICMP) response errors logs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Some routers will send responses to broadcast frames that violate RFC-1122, which fills up a log file system with many useless error messages. An attacker may take advantage of this and attempt to flood the logs with bogus error logs. Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | The runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter can be queried by running the following command: $ sudo sysctl net.ipv4.icmp_ignore_bogus_error_responses net.ipv4.icmp_ignore_bogus_error_responses = 1 If "net.ipv4.icmp_ignore_bogus_error_responses" is not set to "1", this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.icmp_ignore_bogus_error_response | tail -1 net.ipv4.icmp_ignore_bogus_error_response = 1 If "net.ipv4.icmp_ignore_bogus_error_response" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not log bogus ICMP errors: Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.icmp_ignore_bogus_error_responses = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 158 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83961-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable the kernel.core_pattern. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables storing core dumps with the following commands: $ sudo sysctl kernel.core_pattern kernel.core_pattern = |/bin/false If the returned line does not have a value of "|/bin/false", or a line is not returned and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Check that the configuration files are present to disable core dump storage. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.core_pattern | tail -1 kernel.core_pattern = |/bin/false If "kernel.core_pattern" is not set to "|/bin/false" and is not documented with the ISSO as an operational requirement, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable storing core dumps. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: kernel.core_pattern = |/bin/false The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
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| 159 | CCI-003992,CCI-000366 | SRG-OS-000480-GPOS-00227,SRG-OS-000366-GPOS-00153 | CCE-83954-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent the loading of a new kernel for later execution. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling kexec_load prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used subvert the entire secureboot process and should be avoided at all costs especially since it can load unsigned kernel images. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to disable kernel image loading. Check the status of the kernel.kexec_load_disabled kernel parameter with the following command: $ sudo sysctl kernel.kexec_load_disabled kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter with the following command: $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.kexec_load_disabled | tail -1 kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding. |
Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kexec_load_disabled = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 160 | CCI-000366,CCI-001082 | SRG-OS-000132-GPOS-00067,SRG-OS-000480-GPOS-00227 | CCE-83957-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable access to network bpf system call from nonprivileged processes. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Loading and accessing the packet filters programs and maps using the bpf() system call has the potential of revealing sensitive information about the kernel state. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 prevents privilege escalation through the kernel by disabling access to the bpf system call with the following commands: $ sudo sysctl kernel.unprivileged_bpf_disabled kernel.unprivileged_bpf_disabled = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.unprivileged_bpf_disabled | tail -1 kernel.unprivileged_bpf_disabled = 1 If the network parameter "kernel.unprivileged_bpf_disabled" is not equal to "1", or nothing is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent privilege escalation thru the kernel by disabling access to the bpf syscall by adding the following line to a file, in the "/etc/sysctl.d" directory: kernel.unprivileged_bpf_disabled = 1 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
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| 161 | CCI-000366,CCI-001082 | SRG-OS-000132-GPOS-00067,SRG-OS-000480-GPOS-00227 | CCE-83965-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must restrict usage of ptrace to descendant processes. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unrestricted usage of ptrace allows compromised binaries to run ptrace on other processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g., SSH sessions, web browser, etc.) without any additional assistance from the user (i.e., without resorting to phishing). | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 restricts usage of ptrace to descendant processes with the following commands: $ sudo sysctl kernel.yama.ptrace_scope kernel.yama.ptrace_scope = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.yama.ptrace_scope| tail -1 kernel.yama.ptrace_scope = 1 If the network parameter "kernel.yama.ptrace_scope" is not equal to "1", or nothing is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to restrict usage of ptrace to descendant processes by adding the following line to a file, in the "/etc/sysctl.d" directory: kernel.yama.ptrace_scope = 1 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
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| 162 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83966-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must enable hardening for the Berkeley Packet Filter just-in-time compiler. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
When hardened, the extended Berkeley Packet Filter (BPF) just-in-time (JIT) compiler will randomize any kernel addresses in the BPF programs and maps, and will not expose the JIT addresses in "/proc/kallsyms". | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 enables hardening for the BPF JIT with the following commands: $ sudo sysctl net.core.bpf_jit_harden net.core.bpf_jit_harden = 2 If the returned line does not have a value of "2", or a line is not returned, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.core.bpf_jit_harden | tail -1 net.core.bpf_jit_harden = 2 If the network parameter "net.core.bpf_jit_harden" is not equal to "2" or nothing is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enable hardening for the BPF JIT compiler by adding the following line to a file, in the "/etc/sysctl.d" directory: net.core.bpf_jit_harden = 2 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
CAT II | |||||
| 163 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83956-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable the use of user namespaces. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
User namespaces are used primarily for Linux containers. The value "0" disallows the use of user namespaces. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables the use of user namespaces with the following commands: Note: User namespaces are used primarily for Linux containers. If containers are in use, this requirement is Not Applicable. $ sudo sysctl user.max_user_namespaces user.max_user_namespaces = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F user.max_user_namespaces | tail -1 user.max_user_namespaces = 0 If the network parameter "user.max_user_namespaces" is not equal to "0", or nothing is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the use of user namespaces by adding the following line to a file, in the "/etc/sysctl.d" directory: Note: User namespaces are used primarily for Linux containers. If containers are in use, this requirement is Not Applicable. user.max_user_namespaces = 0 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system |
CAT II | |||||
| 164 | CCI-000366,CCI-002824,CCI-001082 | SRG-OS-000132-GPOS-00067,SRG-OS-000433-GPOS-00192,SRG-OS-000480-GPOS-00227 | CCE-83972-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must restrict exposed kernel pointer addresses access. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Exposing kernel pointers (through procfs or "seq_printf()") exposes kernel writeable structures, which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallows any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with "0". | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the runtime status of the kernel.kptr_restrict kernel parameter with the following command: $ sudo sysctl kernel.kptr_restrict kernel.kptr_restrict = 1 Verify the configuration of the kernel.kptr_restrict kernel parameter with the following command: $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.kptr_restrict | tail -1 kernel.kptr_restrict =1 If "kernel.kptr_restrict" is not set to "1" or is missing, this is a finding. |
Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kptr_restrict = 1 Reload settings from all system configuration files with the following command: $ sudo sysctl --system |
CAT II | |||||
| 165 | CCI-000366,CCI-002824 | SRG-OS-000433-GPOS-00193,SRG-OS-000480-GPOS-00227,SRG-APP-000450-CTR-001105 | CCE-83971-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must implement address space layout randomization (ASLR) to protect its memory from unauthorized code execution. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process' address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to repurpose it using return oriented programming (ROP) techniques. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is implementing ASLR with the following command: $ sudo sysctl kernel.randomize_va_space kernel.randomize_va_space = 2 Check that the configuration files are present to enable this kernel parameter. Verify the configuration of the kernel.kptr_restrict kernel parameter with the following command: $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.randomize_va_space | tail -1 kernel.randomize_va_space = 2 If "kernel.randomize_va_space" is not set to "2" or is missing, this is a finding. |
Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.randomize_va_space = 2 Reload settings from all system configuration files with the following command: $ sudo sysctl --system |
CAT II | |||||
| 166 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88983-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local interactive user accounts must be assigned a home directory upon creation. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify all local interactive users on Red Hat Enterprise Linux 9 are assigned a home directory upon creation with the following command: $ grep -i create_home /etc/login.defs CREATE_HOME yes If the value for "CREATE_HOME" parameter is not set to "yes", the line is missing, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to assign home directories to all new local interactive users by setting the "CREATE_HOME" parameter in "/etc/login.defs" to "yes" as follows. CREATE_HOME yes |
CAT II | |||||
| 167 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87451-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Local Red Hat Enterprise Linux 9 initialization files must not execute world-writable programs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that local initialization files do not execute world-writable programs with the following command: Note: The example will be for a system that is configured to create user home directories in the "/home" directory. $ sudo find /home -perm -002 -type f -name ".[^.]*" -exec ls -ld {} \; If any local initialization files are found to reference world-writable files, this is a finding. |
Set the mode on files being executed by the local initialization files with the following command: $ sudo chmod 0755 <file> |
CAT II | |||||
| 168 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87487-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Executable search paths within the initialization files of all local interactive Red Hat Enterprise Linux 9 users must only contain paths that resolve to the system default or the users home directory. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory (other than the users home directory), executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. If deviations from the default system search path for the local interactive user are required, they must be documented with the information system security officer (ISSO). |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that all local interactive user initialization file executable search path statements do not contain statements that will reference a working directory other than user home directories with the following commands: $ sudo grep -i path= /home/*/.* /home/[localinteractiveuser]/.bash_profile:PATH=$PATH:$HOME/.local/bin:$HOME/bin If any local interactive user initialization files have executable search path statements that include directories outside of their home directory and is not documented with the ISSO as an operational requirement, this is a finding. |
Edit the local interactive user initialization files to change any PATH variable statements that reference directories other than their home directory. If a local interactive user requires path variables to reference a directory owned by the application, it must be documented with the ISSO. |
CAT II | |||||
| 169 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88964-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local interactive users must have a home directory assigned in the /etc/passwd file. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that interactive users on the system have a home directory assigned with the following command: $ sudo awk -F: '($3>=1000)&&($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd smithk:x:1000:1000:smithk:/home/smithk:/bin/bash scsaustin:x:1001:1001:scsaustin:/home/scsaustin:/bin/bash djohnson:x:1002:1002:djohnson:/home/djohnson:/bin/bash Inspect the output and verify that all interactive users (normally users with a user identifier (UID) greater that 1000) have a home directory defined. If users home directory is not defined, this is a finding. |
Create and assign home directories to all local interactive users on Red Hat Enterprise Linux 9 that currently do not have a home directory assigned. | CAT II | |||||
| 170 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83639-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | All Red Hat Enterprise Linux 9 local interactive user home directories defined in the /etc/passwd file must exist. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a denial of service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the assigned home directories of all interactive users on the system exist with the following command: $ sudo pwck -r user 'mailnull': directory 'var/spool/mqueue' does not exist The output should not return any interactive users. If users home directory does not exist, this is a finding. |
Create home directories to all local interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in "/etc/ passwd": Note: The example will be for the user wadea, who has a home directory of "/home/wadea", a user identifier (UID) of "wadea", and a Group Identifier (GID) of "users assigned" in "/etc/passwd". $ sudo mkdir /home/wadea $ sudo chown wadea /home/wadea $ sudo chgrp users /home/wadea $ sudo chmod 0750 /home/wadea |
CAT II | |||||
| 171 | CCI-000366 | SRG-OS-000480-GPOS-00228,SRG-OS-000480-GPOS-00227 | CCE-83644-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must define default permissions for the bash shell. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the "umask" setting is configured correctly in the "/etc/bashrc" file with the following command: Note: If the value of the "umask" parameter is set to "000" "/etc/bashrc" file, the Severity is raised to a CAT I. $ grep umask /etc/bashrc umask 077 umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to define default permissions for all authenticated users using the bash shell. Add or edit the lines for the "umask" parameter in the "/etc/bashrc" file to "077": umask 077 |
CAT II | |||||
| 172 | CCI-000366 | SRG-OS-000480-GPOS-00227,SRG-OS-000480-GPOS-00228 | CCE-90365-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must set the umask value to 077 for all local interactive user accounts. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the default umask for all local interactive users is "077". Identify the locations of all local interactive user home directories by looking at the "/etc/passwd" file. Check all local interactive user initialization files for interactive users with the following command: Note: The example is for a system that is configured to create users home directories in the "/home" directory. $ sudo grep -ir umask /home /home/smithj/.bash_history:grep -i umask /etc/bashrc /etc/csh.cshrc /etc/profile /home/smithj/.bash_history:grep -i umask /etc/login.defs If any local interactive user initialization files are found to have a umask statement that sets a value less restrictive than "077", this is a finding. |
Remove the umask statement from all local interactive user's initialization files. If the account is for an application, the requirement for a umask less restrictive than "077" can be documented with the Information System Security Officer, but the user agreement for access to the account must specify that the local interactive user must log on to their account first and then switch the user to the application account with the correct option to gain the account's environment variables. |
CAT II | |||||
| 173 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88048-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have unauthorized accounts. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Accounts providing no operational purpose provide additional opportunities for system compromise. Unnecessary accounts include user accounts for individuals not requiring access to the system and application accounts for applications not installed on the system. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that there are no unauthorized local interactive user accounts with the following command: $ less /etc/passwd root:x:0:0:root:/root:/bin/bash ... smithk:x:1000:1000:smithk:/home/smithk:/bin/bash throckw:x:1001:1001:throckw:/home/throckw:/bin/bash Interactive user account, generally will have a UID of 1000 or greater, a home directory in a specific partition, and an interactive shell. Obtain the list of interactive user accounts authorized to be on the system from the System Administrator or Information System Security Officer (ISSO) and compare it to the list of local interactive user accounts on the system. If there are unauthorized local user accounts on the system, this is a finding. |
Remove unauthorized local interactive user accounts with the following command where <unauthorized_user> is the unauthorized account: $ sudo userdel <unauthorized_user> |
CAT II | |||||
| 174 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83624-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The root account must be the only account having unrestricted access to Red Hat Enterprise Linux 9 system. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An account has root authority if it has a user identifier (UID) of "0". Multiple accounts with a UID of "0" afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that only the "root" account has a UID "0" assignment with the following command: $ awk -F: '$3 == 0 {print $1}' /etc/passwd root If any accounts other than "root" have a UID of "0", this is a finding. |
Change the UID of any account on the system, other than root, that has a UID of "0". If the account is associated with system commands or applications, the UID should be changed to one greater than "0" but less than "1000". Otherwise, assign a UID of greater than "1000" that has not already been assigned. |
CAT II | |||||
| 175 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83611-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not allow blank or null passwords. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that null passwords cannot be used with the following command: $ sudo grep -i nullok /etc/pam.d/system-auth /etc/pam.d/password-auth If output is produced, this is a finding. |
Remove any instances of the "nullok" option in the "/etc/pam.d/password-auth" and "/etc/pam.d/system-auth" files to prevent logons with empty passwords. Note: Manual changes to the listed file may be overwritten by the "authselect" program. |
CAT II | |||||
| 176 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83623-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 system accounts must not have an interactive login shell. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that system accounts must not have an interactive login shell with the following command: $ awk -F: '($3<1000){print $1 ":" $3 ":" $7}' /etc/passwd root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin Identify the system accounts from this listing that do not have a nologin shell. If any system account (other than the root account) has a login shell and it is not documented with the information system security officer (ISSO), this is a finding. |
Configure Red Hat Enterprise Linux 9 so that all noninteractive accounts on the system do not have an interactive shell assigned to them. If the system account needs a shell assigned for mission operations, document the need with the information system security officer (ISSO). Run the following command to disable the interactive shell for a specific noninteractive user account: Replace <user> with the user that has a login shell. $ sudo usermod --shell /sbin/nologin <user> Do not perform the steps in this section on the root account. Doing so will cause the system to become inaccessible. |
CAT II | |||||
| 177 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83529-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use the invoking user's password for privilege escalation when using "sudo". | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the rootpw, targetpw, or runaspw flags are defined and not disabled, by default the operating system will prompt the invoking user for the "root" user password. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the sudoers security policy is configured to use the invoking user's password for privilege escalation with the following command: $ sudo egrep -ir '(!rootpw|!targetpw|!runaspw)' /etc/sudoers /etc/sudoers.d/* | grep -v '#' /etc/sudoers:Defaults !targetpw /etc/sudoers:Defaults !rootpw /etc/sudoers:Defaults !runaspw If no results are returned, this is a finding. If results are returned from more than one file location, this is a finding. If "Defaults !targetpw" is not defined, this is a finding. If "Defaults !rootpw" is not defined, this is a finding. If "Defaults !runaspw" is not defined, this is a finding. |
Define the following in the Defaults section of the /etc/sudoers file or a single configuration file in the /etc/sudoers.d/ directory: Defaults !targetpw Defaults !rootpw Defaults !runaspw |
CAT II | |||||
| 178 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83525-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must restrict privilege elevation to authorized personnel. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If the "sudoers" file is not configured correctly, any user defined on the system can initiate privileged actions on the target system. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 restricts privilege elevation to authorized personnel with the following command: $ sudo sh -c 'grep -iw ALL /etc/sudoers /etc/sudoers.d/*' If the either of the following entries are returned, this is a finding: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL |
Remove the following entries from the /etc/sudoers file or configuration file under /etc/sudoers.d/: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL |
CAT II | |||||
| 179 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-85972-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must not have accounts configured with blank or null passwords. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that null or blank passwords cannot be used with the following command: $ sudo awk -F: '!$2 {print $1}' /etc/shadow If the command returns any results, this is a finding. |
Configure all accounts on Red Hat Enterprise Linux 9 to have a password or lock the account with the following commands: Perform a password reset: $ sudo passwd [username] To lock an account: $ sudo passwd -l [username] |
CAT II | |||||
| 180 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84105-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The graphical display manager must not be the default target on Red Hat Enterprise Linux 9 unless approved. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to boot to the command line: $ systemctl get-default multi-user.target If the system default target is not set to "multi-user.target" and the information system security officer (ISSO) lacks a documented requirement for a graphical user interface, this is a finding. |
Document the requirement for a graphical user interface with the ISSO or set the default target to multi-user with the following command: $ sudo systemctl set-default multi-user.target |
CAT II | |||||
| 181 | CCI-000778,CCI-000366,CCI-001958 | SRG-OS-000114-GPOS-00059,SRG-OS-000378-GPOS-00163,SRG-OS-000480-GPOS-00227 | CCE-90128-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent a user from overriding the disabling of the graphical user interface automount function. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A nonprivileged account is any operating system account with authorizations of a nonprivileged user. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables ability of the user to override the graphical user interface automount setting. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that the automount setting is locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep 'automount-open' /etc/dconf/db/local.d/locks/* /org/gnome/desktop/media-handling/automount-open If the command does not return at least the example result, this is a finding. |
Configure the GNOME desktop to not allow a user to change the setting that disables automated mounting of removable media. Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/media-handling/automount-open Then update the dconf system databases: $ sudo dconf update |
CAT II | |||||
| 182 | CCI-000366,CCI-001764,CCI-001958,CCI-000778 | SRG-OS-000114-GPOS-00059,SRG-OS-000378-GPOS-00163,SRG-OS-000480-GPOS-00227 | CCE-90257-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent a user from overriding the disabling of the graphical user interface autorun function. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables ability of the user to override the graphical user interface autorun setting. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that the automount setting is locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep 'autorun-never' /etc/dconf/db/local.d/locks/* /org/gnome/desktop/media-handling/autorun-never If the command does not return at least the example result, this is a finding. |
Configure the GNOME desktop to not allow a user to change the setting that disables autorun on removable media. Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/media-handling/autorun-never Then update the dconf system databases: $ sudo dconf update |
CAT II | |||||
| 183 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88653-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that users cannot enable the Ctrl-Alt-Del sequence in the GNOME desktop with the following command: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ grep logout /etc/dconf/db/local.d/locks/* /org/gnome/settings-daemon/plugins/media-keys/logout If the output is not "/org/gnome/settings-daemon/plugins/media-keys/logout", the line is commented out, or the line is missing, this is a finding. If Gnome is configured to shut down when Ctrl-Alt-Del is pressed, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop. Create a database to container system-wide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting: /org/gnome/settings-daemon/plugins/media-keys/logout Run the following command to update the database: $ sudo dconf update |
CAT II | |||||
| 184 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88285-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable the user list at logon for graphical user interfaces. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the user logon list for graphical user interfaces with the following command: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ sudo gsettings get org.gnome.login-screen disable-user-list true If the setting is "false", this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the user list at logon for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/02-login-screen [org/gnome/login-screen] disable-user-list=true Update the system databases: $ sudo dconf update |
CAT II | |||||
| 185 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86315-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must prevent a user from overriding the disable-restart-buttons setting for the graphical user interface. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents a user from overriding the disable-restart-buttons setting for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep disable-restart-buttons /etc/dconf/db/local.d/locks/* /org/gnome/login-screen/disable-restart-buttons If the command does not return at least the example result, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding the disable-restart-buttons setting for graphical user interfaces. Create a database to contain the system-wide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following line to prevent nonprivileged users from modifying it: /org/gnome/login-screen/disable-restart-buttons Run the following command to update the database: $ sudo dconf update |
CAT II | |||||
| 186 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87295-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 effective dconf policy must match the policy keyfiles. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unlike text-based keyfiles, the binary database is impossible to check through most automated and all manual means; therefore, in order to evaluate dconf configuration, both have to be true at the same time - configuration files have to be compliant, and the database needs to be more recent than those keyfiles, which gives confidence that it reflects them. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Check the last modification time of the local databases, comparing it to the last modification time of the related keyfiles. The following command will check every dconf database and compare its modification time to the related system keyfiles: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ function dconf_needs_update { for db in $(find /etc/dconf/db -maxdepth 1 -type f); do db_mtime=$(stat -c %Y "$db"); keyfile_mtime=$(stat -c %Y "$db".d/* | sort -n | tail -1); if [ -n "$db_mtime" ] && [ -n "$keyfile_mtime" ] && [ "$db_mtime" -lt "$keyfile_mtime" ]; then echo "$db needs update"; return 1; fi; done; }; dconf_needs_update If the command has any output, then a dconf database needs to be updated, and this is a finding. |
Update the dconf databases by running the following command: $ sudo dconf update |
CAT II | |||||
| 187 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83468-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | A separate Red Hat Enterprise Linux 9 file system must be used for user home directories (such as /home or an equivalent). | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Ensuring that "/home" is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for "/home" with the following command: $ mount | grep /home UUID=fba5000f-2ffa-4417-90eb-8c54ae74a32f on /home type ext4 (rw,nodev,nosuid,noexec,seclabel) If a separate entry for "/home" is not in use, this is a finding. |
Migrate the "/home" directory onto a separate file system/partition. | CAT II | |||||
| 188 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90845-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a separate file system for /tmp. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/tmp" partition is used as temporary storage by many programs. Placing "/tmp" in its own partition enables the setting of more restrictive mount options, which can help protect programs that use it. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for "/tmp" with the following command: $ mount | grep /tmp tmpfs /tmp tmpfs noatime,mode=1777 0 0 If a separate entry for "/tmp" is not in use, this is a finding. |
Migrate the "/tmp" path onto a separate file system. | CAT II | |||||
| 189 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83466-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a separate file system for /var. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Ensuring that "/var" is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the "/var" directory to contain world-writable directories installed by other software packages. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for "/var" with the following command: $ mount | grep /var UUID=c274f65f-c5b5-4481-b007-bee96feb8b05 /var xfs noatime 1 2 If a separate entry for "/var" is not in use, this is a finding. |
Migrate the "/var" path onto a separate file system. | CAT II | |||||
| 190 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90848-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a separate file system for /var/log. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Placing "/var/log" in its own partition enables better separation between log files and other files in "/var/". | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for "/var/log" with the following command: $ mount | grep /var/log UUID=c274f65f-c5b5-4486-b021-bee96feb8b21 /var/log xfs noatime 1 2 If a separate entry for "/var/log" is not in use, this is a finding. |
Migrate the "/var/log" path onto a separate file system. | CAT II | |||||
| 191 | CCI-000366,CCI-001849 | SRG-OS-000341-GPOS-00132,SRG-OS-000480-GPOS-00227,SRG-APP-000357-CTR-000800 | CCE-90847-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a separate file system for the system audit data path. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Placing "/var/log/audit" in its own partition enables better separation between audit files and other system files, and helps ensure that auditing cannot be halted due to the partition running out of space. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for the system audit data path with the following command: Note: /var/log/audit is used as the example as it is a common location. $ mount | grep /var/log/audit UUID=2efb2979-45ac-82d7-0ae632d11f51 on /var/log/home type xfs (rw,realtime,seclabel,attr2,inode64) If no line is returned, this is a finding. |
Migrate the system audit data path onto a separate file system. | CAT II | |||||
| 192 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83487-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use a separate file system for /var/tmp. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The "/var/tmp" partition is used as temporary storage by many programs. Placing "/var/tmp" in its own partition enables the setting of more restrictive mount options, which can help protect programs that use it. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a separate file system/partition has been created for "/var/tmp" with the following command: $ mount | grep /var/tmp UUID=c274f65f-c5b5-4379-b017-bee96feb7a34 /var/log xfs noatime 1 2 If a separate entry for "/var/tmp" is not in use, this is a finding. |
Migrate the "/var/tmp" path onto a separate file system. | CAT II | |||||
| 193 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83994-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use cron logging. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Cron logging can be used to trace the successful or unsuccessful execution of cron jobs. It can also be used to spot intrusions into the use of the cron facility by unauthorized and malicious users. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that "rsyslog" is configured to log cron events with the following command: Note: If another logging package is used, substitute the utility configuration file for "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files. $ sudo grep -s cron /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.info;mail.none;authpriv.none;cron.none /var/log/messages /etc/rsyslog.conf:cron.* /var/log/cron If the command does not return a response, check for cron logging all facilities with the following command: $ sudo grep -s /var/log/messages /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.info;mail.none;authpriv.none;cron.none /var/log/messages If "rsyslog" is not logging messages for the cron facility or all facilities, this is a finding. |
Configure "rsyslog" to log all cron messages by adding or updating the following line to "/etc/rsyslog.conf" or a configuration file in the /etc/rsyslog.d/ directory: cron.* /var/log/cron The rsyslog daemon must be restarted for the changes to take effect: $ sudo systemctl restart rsyslog.service |
CAT II | |||||
| 194 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83995-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that the rsyslog daemon does not accept log messages from other servers unless the server is being used for log aggregation. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unintentionally running a rsyslog server accepting remote messages puts the system at increased risk. Malicious rsyslog messages sent to the server could exploit vulnerabilities in the server software itself, could introduce misleading information into the system's logs, or could fill the system's storage leading to a denial of service. If the system is intended to be a log aggregation server, its use must be documented with the information system security officer (ISSO). |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is not configured to receive remote logs using rsyslog with the following commands: $ grep -i modload /etc/rsyslog.conf /etc/rsyslog.d/* $ModLoad imtcp $ModLoad imrelp $ grep -i serverrun /etc/rsyslog.conf /etc/rsyslog.d/* $InputTCPServerRun 514 $InputRELPServerRun 514 Note: An error about no files or directories may be returned. This is not a finding. If any lines are returned by the command, then rsyslog is configured to receive remote messages, and this is a finding. |
Configure Red Hat Enterprise Linux 9 to not receive remote logs using rsyslog. Remove the lines in /etc/rsyslog.conf and any files in the /etc/rsyslog.d directory that match any of the following: $ModLoad imtcp $ModLoad imudp $ModLoad imrelp $InputTCPServerRun [0-9]* $UDPServerRun [0-9]* $InputRELPServerRun [0-9]* The rsyslog daemon must be restarted for the changes to take effect: $ sudo systemctl restart rsyslog.service |
CAT II | |||||
| 195 | CCI-000366,CCI-001851 | SRG-OS-000479-GPOS-00224,SRG-OS-000480-GPOS-00227,SRG-OS-000342-GPOS-00133 | CCE-83990-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured to forward audit records via TCP to a different system or media from the system being audited via rsyslog. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. Red Hat Enterprise Linux 9 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS and DTLS protocols) creates a method to securely encrypt and offload auditing. Rsyslog provides three ways to forward message: the traditional UDP transport, which is extremely lossy but standard; the plain TCP based transport, which loses messages only during certain situations but is widely available; and the RELP transport, which does not lose messages but is currently available only as part of the rsyslogd 3.15.0 and above. Examples of each configuration: UDP *.* @remotesystemname TCP *.* @@remotesystemname RELP *.* :omrelp:remotesystemname:2514 Note that a port number was given as there is no standard port for RELP. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 audit system offloads audit records onto a different system or media from the system being audited via rsyslog using TCP with the following command: $ sudo grep @@ /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.* @@[remoteloggingserver]:[port] If a remote server is not configured, or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the audit logs are being offloaded to another system or media, this is a finding. |
Configure Red Hat Enterprise Linux 9 to offload audit records onto a different system or media from the system being audited via TCP using rsyslog by specifying the remote logging server in "/etc/rsyslog.conf"" or "/etc/rsyslog.d/[customfile].conf" with the name or IP address of the log aggregation server. *.* @@[remoteloggingserver]:[port]" |
CAT II | |||||
| 196 | CCI-000778,CCI-001958,CCI-003959 | SRG-OS-000114-GPOS-00059,SRG-OS-000378-GPOS-00163,SRG-OS-000480-GPOS-00227,SRG-APP-000141-CTR-000315 | CCE-83851-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured to disable USB mass storage. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the ability to load the USB Storage kernel module with the following command: $ sudo grep -r usb-storage /etc/modprobe.conf /etc/modprobe.d/* blacklist usb-storage If the command does not return any output, or the line is commented out, and use of USB Storage is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
To configure the system to prevent the usb-storage kernel module from being loaded, add the following line to the file /etc/modprobe.d/usb-storage.conf (or create usb-storage.conf if it does not exist): install usb-storage /bin/false blacklist usb-storage |
CAT II | |||||
| 197 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83984-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable core dump backtraces. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables core dump backtraces by issuing the following command: $ grep -i process /etc/systemd/coredump.conf ProcessSizeMax=0 If the "ProcessSizeMax" item is missing, commented out, or the value is anything other than "0" and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding. |
Configure the operating system to disable core dump backtraces. Add or modify the following line in /etc/systemd/coredump.conf: ProcessSizeMax=0 |
CAT II | |||||
| 198 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83979-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable storing core dumps. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables storing core dumps for all users by issuing the following command: $ grep -i storage /etc/systemd/coredump.conf Storage=none If the "Storage" item is missing, commented out, or the value is anything other than "none" and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding. |
Configure the operating system to disable storing core dumps for all users. Add or modify the following line in /etc/systemd/coredump.conf: Storage=none |
CAT II | |||||
| 199 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83980-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable core dumps for all users. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables core dumps for all users by issuing the following command: $ grep -r -s core /etc/security/limits.conf /etc/security/limits.d/*.conf /etc/security/limits.conf:* hard core 0 This can be set as a global domain (with the * wildcard) but may be set differently for multiple domains. If the "core" item is missing, commented out, or the value is anything other than "0" and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding. |
Configure the operating system to disable core dumps for all users. Add the following line to the top of the /etc/security/limits.conf or in a single ".conf" file defined in /etc/security/limits.d/: * hard core 0 |
CAT II | |||||
| 200 | CCI-000366,CCI-002235 | SRG-OS-000324-GPOS-00125,SRG-OS-000480-GPOS-00227 | CCE-90308-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The systemd Ctrl-Alt-Delete burst key sequence in Red Hat Enterprise Linux 9 must be disabled. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds with the following command: $ grep -i ctrl /etc/systemd/system.conf CtrlAltDelBurstAction=none If the "CtrlAltDelBurstAction" is not set to "none", commented out, or is missing, this is a finding. |
Configure the system to disable the CtrlAltDelBurstAction by added or modifying the following line in the "/etc/systemd/system.conf" configuration file: CtrlAltDelBurstAction=none Reload the daemon for this change to take effect. $ sudo systemctl daemon-reload |
CAT II | |||||
| 201 | CCI-000366,CCI-002235 | SRG-OS-000324-GPOS-00125,SRG-OS-000480-GPOS-00227 | CCE-86667-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | The x86 Ctrl-Alt-Delete key sequence must be disabled on Red Hat Enterprise Linux 9. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
A locally logged-on user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is not configured to reboot the system when Ctrl-Alt-Delete is pressed with the following command: $ sudo systemctl status ctrl-alt-del.target ctrl-alt-del.target Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.) Active: inactive (dead) If the "ctrl-alt-del.target" is loaded and not masked, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the ctrl-alt-del.target with the following command: $ sudo systemctl disable --now ctrl-alt-del.target $ sudo systemctl mask --now ctrl-alt-del.target |
CAT II | |||||
| 202 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90837-6 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that the file integrity tool verifies Access Control Lists (ACLs). | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Red Hat Enterprise Linux 9 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. ACLs can provide permissions beyond those permitted through the file mode and must be verified by the file integrity tools. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that that AIDE is verifying ACLs with the following command: $ grep acl /etc/aide.conf All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "acl" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or ACLs are not being checked by another file integrity tool, this is a finding. |
Configure the file integrity tool to check file and directory ACLs. If AIDE is installed, ensure the "acl" rule is present on all uncommented file and directory selection lists. |
CAT II | |||||
| 203 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83439-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that the file integrity tool verifies extended attributes. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Red Hat Enterprise Linux 9 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that AIDE is configured to verify extended attributes with the following command: $ grep xattrs /etc/aide.conf All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "xattrs" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or extended attributes are not being checked by another file integrity tool, this is a finding. |
Configure the file integrity tool to check file and directory extended attributes. If AIDE is installed, ensure the "xattrs" rule is present on all uncommented file and directory selection lists. |
CAT II | |||||
| 204 | CCI-000366,CCI-001084 | SRG-OS-000480-GPOS-00227,SRG-OS-000134-GPOS-00068 | CCE-83842-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable virtual system calls. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
System calls are special routines in the Linux kernel, which userspace applications ask to do privileged tasks. Invoking a system call is an expensive operation because the processor must interrupt the currently executing task and switch context to kernel mode and then back to userspace after the system call completes. Virtual system calls map into user space a page that contains some variables and the implementation of some system calls. This allows the system calls to be executed in userspace to alleviate the context switching expense. Virtual system calls provide an opportunity of attack for a user who has control of the return instruction pointer. Disabling virtual system calls help to prevent return oriented programming (ROP) attacks via buffer overflows and overruns. If the system intends to run containers based on RHEL 6 components, then virtual system calls will need enabled so the components function properly. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the current GRUB 2 configuration disables virtual system calls with the following command: $ sudo grubby --info=ALL | grep args | grep -v 'vsyscall=none' If any output is returned, this is a finding. Check that virtual system calls are disabled by default to persist in kernel updates with the following command: $ sudo grep vsyscall /etc/default/grub GRUB_CMDLINE_LINUX="vsyscall=none" If "vsyscall" is not set to "none", is missing or commented out, and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Document the use of virtual system calls with the ISSO as an operational requirement or disable them with the following command: $ sudo grubby --update-kernel=ALL --args="vsyscall=none" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="vsyscall=none" |
CAT II | |||||
| 205 | CCI-000366,CCI-001084 | SRG-OS-000480-GPOS-00227,SRG-OS-000134-GPOS-00068 | CCE-83985-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must clear the page allocator to prevent use-after-free attacks. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that GRUB 2 is configured to enable page poisoning to mitigate use-after-free vulnerabilities. Check that the current GRUB 2 configuration has page poisoning enabled with the following command: $ sudo grubby --info=ALL | grep args | grep -v 'page_poison=1' If any output is returned, this is a finding. Check that page poisoning is enabled by default to persist in kernel updates with the following command: $ sudo grep page_poison /etc/default/grub GRUB_CMDLINE_LINUX="page_poison=1" If "page_poison" is not set to "1", is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enable page poisoning with the following commands: $ sudo grubby --update-kernel=ALL --args="page_poison=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="page_poison=1" |
CAT II | |||||
| 206 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87114-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must disable the ability of systemd to spawn an interactive boot process. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Using interactive or recovery boot, the console user could disable auditing, firewalls, or other services, weakening system security. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that GRUB 2 is configured to disable interactive boot. Check that the current GRUB 2 configuration disables the ability of systemd to spawn an interactive boot process with the following command: $ sudo grubby --info=ALL | grep args | grep 'systemd.confirm_spawn' If any output is returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to allocate sufficient audit_backlog_limit to disable the ability of systemd to spawn an interactive boot process with the following command: $ sudo grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn" |
CAT II | |||||
| 207 | CCI-000366 | SRG-OS-000297-GPOS-00115 | CCE-86049-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | A Red Hat Enterprise Linux 9 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DOD data. Red Hat Enterprise Linux 9 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be utilized to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the Red Hat Enterprise Linux 9 "firewalld" is configured to employ a deny-all, allow-by-exception policy for allowing connections to other systems with the following commands: $ sudo firewall-cmd --state running $ sudo firewall-cmd --get-active-zones public interfaces: ens33 $ sudo firewall-cmd --info-zone=public | grep target target: DROP $ sudo firewall-cmd --permanent --info-zone=public | grep target target: DROP If no zones are active on the Red Hat Enterprise Linux 9 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding. |
Configure the "firewalld" daemon to employ a deny-all, allow-by-exception with the following commands: Start by adding the exceptions that are required for mission functionality to the "drop" zone. If SSH access on port 22 is needed, for example, run the following: "sudo firewall-cmd --permanent --add-service=ssh --zone=drop" Reload the firewall rules to update the runtime configuration from the "--permanent" changes made above: $ sudo firewall-cmd --reload Set the default zone to the drop zone: $ sudo firewall-cmd --set-default-zone=drop Note: This is a runtime and permanent change. Add any interfaces to the newly modified "drop" zone: $ sudo firewall-cmd --permanent --zone=drop --change-interface=ens33 Reload the firewall rules for changes to take effect: $ sudo firewall-cmd --reload |
CAT II | |||||
| 208 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86858-8 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 systems using Domain Name Servers (DNS) resolution must have at least two name servers configured. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
To provide availability for name resolution services, multiple redundant name servers are mandated. A failure in name resolution could lead to the failure of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the name servers used by the system with the following command: $ grep nameserver /etc/resolv.conf nameserver 192.168.1.2 nameserver 192.168.1.3 If less than two lines are returned that are not commented out, this is a finding. |
Configure the operating system to use two or more name servers for DNS resolution based on the DNS mode of the system. If the NetworkManager DNS mode is set to "none", then add the following lines to "/etc/resolv.conf": nameserver [name server 1] nameserver [name server 2] Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers. If the NetworkManager DNS mode is set to "default" then add two DNS servers to a NetworkManager connection. Using the following commands: $ sudo nmcli connection modify [connection name] ipv4.dns [name server 1] $ sudo nmcli connection modify [connection name] ipv4.dns [name server 2] Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers. Replace [connection name] with a valid NetworkManager connection name on the system. Replace ipv4 with ipv6 if IPv6 DNS servers are used. |
CAT II | |||||
| 209 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83996-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 network interfaces must not be in promiscuous mode. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Network interfaces in promiscuous mode allow for the capture of all network traffic visible to the system. If unauthorized individuals can access these applications, it may allow them to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the information systems security officer (ISSO) and restricted to only authorized personnel. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify network interfaces are not in promiscuous mode with the following command: $ ip link | grep -i promisc If network interfaces are found on the system in promiscuous mode and their use has not been approved by the ISSO and documented, this is a finding. |
Configure network interfaces to turn off promiscuous mode unless approved by the ISSO and documented. Set the promiscuous mode of an interface to off with the following command: $ sudo ip link set dev <devicename> multicast off promisc off |
CAT II | |||||
| 210 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-87232-5 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured to prevent unrestricted mail relaying. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If unrestricted mail relaying is permitted, unauthorized senders could use this host as a mail relay for the purpose of sending spam or other unauthorized activity. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to prevent unrestricted mail relaying with the following command: $ postconf -n smtpd_client_restrictions smtpd_client_restrictions = permit_mynetworks,reject If the "smtpd_client_restrictions" parameter contains any entries other than "permit_mynetworks" and "reject", and the additional entries have not been documented with the information system security officer (ISSO), this is a finding. |
Modify the postfix configuration file to restrict client connections to the local network with the following command: $ sudo postconf -e 'smtpd_client_restrictions = permit_mynetworks,reject' |
CAT II | |||||
| 211 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84023-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | A Red Hat Enterprise Linux 9 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DoD data. Red Hat Enterprise Linux 9 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be utilized to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify the Red Hat Enterprise Linux 9 "firewalld" is configured to employ a deny-all, allow-by-exception policy for allowing connections to other systems with the following commands: $ sudo firewall-cmd --state running $ sudo firewall-cmd --get-active-zones public interfaces: ens33 $ sudo firewall-cmd --info-zone=public | grep target target: DROP $ sudo firewall-cmd --permanent --info-zone=public | grep target target: DROP If no zones are active on the Red Hat Enterprise Linux 9 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding. |
Configure the "firewalld" daemon to employ a deny-all, allow-by-exception with the following commands: Start by adding the exceptions that are required for mission functionality to the "drop" zone. If you need SSH access on port 22, for example, run the following: "sudo firewall-cmd --permanent --add-service=ssh --zone=drop" Reload the firewall rules to update the runtime configuration from the "--permanent" changes made above: $ sudo firewall-cmd --reload Set the default zone to the drop zone: $ sudo firewall-cmd --set-default-zone=drop Note: This is a runtime and permanent change. Add any interfaces to the newly modified "drop" zone: $ sudo firewall-cmd --permanent --zone=drop --change-interface=ens33 Reload the firewall rules for changes to take effect: $ sudo firewall-cmd --reload |
CAT II | |||||
| 212 | CCI-000382 | SRG-OS-000096-GPOS-00050 | CCE-89175-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the Ports, Protocols, and Services Management (PPSM) Category Assignments List (CAL) and vulnerability assessments. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary ports, protocols, and services on information systems. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Inspect the firewall configuration and running services to verify it is configured to prohibit or restrict the use of functions, ports, protocols, and/or services that are unnecessary or prohibited. Check which services are currently active with the following command: $ sudo firewall-cmd --list-all-zones custom (active) target: DROP icmp-block-inversion: no interfaces: ens33 sources: services: dhcpv6-client dns http https ldaps rpc-bind ssh ports: masquerade: no forward-ports: icmp-blocks: rich rules: Ask the system administrator for the site or program Ports, Protocols, and Services Management Component Local Service Assessment (PPSM CLSA). Verify the services allowed by the firewall match the PPSM CLSA. If there are additional ports, protocols, or services that are not in the PPSM CLSA, or there are ports, protocols, or services that are prohibited by the PPSM Category Assurance List (CAL), this is a finding. |
Update the host's firewall settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL. Then run the following command to load the newly created rule(s): $ sudo firewall-cmd --reload |
CAT II | |||||
| 213 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86805-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | {{ full_name }} must configure a DNS processing mode set be Network Manager. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | [main] dns=none If the dns key under main does not exist or is not set to "none" or "default", this is a finding. |
Configure NetworkManager in RHEL 9 to use a DNS mode. In "/etc/NetworkManager/NetworkManager.conf" add the following line in the "[main]" section: dns = none |
CAT II | ||||||
| 214 | CCI-000213 | SRG-OS-000480-GPOS-00227 | CCE-89732-2 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | CAT II | |||||||||
| 215 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90208-0 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | There must be no shosts.equiv files on Red Hat Enterprise Linux 9. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The shosts.equiv files are used to configure host-based authentication for the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify there are no "shosts.equiv" files on Red Hat Enterprise Linux 9 with the following command: $ sudo find / -name shosts.equiv If a "shosts.equiv" file is found, this is a finding. |
Remove any found "shosts.equiv" files from the system. $ sudo rm /[path]/[to]/[file]/shosts.equiv |
CAT II | |||||
| 216 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-86532-9 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | There must be no .shosts files on Red Hat Enterprise Linux 9. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
The .shosts files are used to configure host-based authentication for individual users or the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify there are no ".shosts" files on Red Hat Enterprise Linux 9 with the following command: $ sudo find / -name .shosts If a ".shosts" file is found, this is a finding. |
Remove any found ".shosts" files from the system. $ sudo rm /[path]/[to]/[file]/.shosts |
CAT II | |||||
| 217 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83560-3 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must display the date and time of the last successful account logon upon logon. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Users need to be aware of activity that occurs regarding their account. Providing users with information regarding the number of unsuccessful attempts that were made to login to their account allows the user to determine if any unauthorized activity has occurred and gives them an opportunity to notify administrators. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify users are provided with feedback on when account accesses last occurred with the following command: $ sudo grep pam_lastlog /etc/pam.d/postlogin session required pam_lastlog.so showfailed If "pam_lastlog" is missing from "/etc/pam.d/postlogin" file, or the silent option is present, this is a finding. |
Configure Red Hat Enterprise Linux 9 to provide users with feedback on when account accesses last occurred by setting the required configuration options in "/etc/pam.d/postlogin". Add the following line to the top of "/etc/pam.d/postlogin": session required pam_lastlog.so showfailed |
CAT II | |||||
| 218 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-83453-1 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be a vendor-supported release. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
An operating system release is considered "supported" if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve security issues discovered in the system software. Red Hat offers the Extended Update Support (EUS) ad-on to a Red Hat Enterprise Linux subscription, for a fee, for those customers who wish to standardize on a specific minor release for an extended period. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that the version or Red Hat Enterprise Linux 9 is vendor supported with the following command: $ cat /etc/redhat-release Red Hat Enterprise Linux release 9.0 (Plow) If the installed version of Red Hat Enterprise Linux 9 is not supported, this is a finding. |
Upgrade to a supported version of Red Hat Enterprise Linux 9. | CAT II | |||||
| 219 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-85920-7 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must be configured so that all system device files are correctly labeled to prevent unauthorized modification. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
If an unauthorized or modified device is allowed to exist on the system, there is the possibility the system may perform unintended or unauthorized operations. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that all system device files are correctly labeled to prevent unauthorized modification. List all device files on the system that are incorrectly labeled with the following commands: Note: Device files are normally found under "/dev", but applications may place device files in other directories and may necessitate a search of the entire system. # find /dev -context *:device_t:* \( -type c -o -type b \) -printf "%p %Z " # find /dev -context *:unlabeled_t:* \( -type c -o -type b \) -printf "%p %Z " Note: There are device files, such as "/dev/vmci", that are used when the operating system is a host virtual machine. They will not be owned by a user on the system and require the "device_t" label to operate. These device files are not a finding. If there is output from either of these commands, other than already noted, this is a finding. |
Restore the SELinux policy for the affected device file from the system policy database using the following command: $ sudo restorecon -v <device_path> Substituting "<device_path>" with the path to the affected device file (from the output of the previous commands). An example device file path would be "/dev/ttyUSB0". If the output of the above command does not indicate that the device was relabeled to a more specific SELinux type label, then the SELinux policy of the system must be updated with more specific policy for the device class specified. If a package was used to install support for a device class, that package could be reinstalled using the following command: $ sudo dnf reinstall <package_name> If a package was not used to install the SELinux policy for a given device class, then it must be generated manually and provide specific type labels. |
CAT II | |||||
| 220 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-84106-4 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | A graphical display manager must not be installed on Red Hat Enterprise Linux 9 unless approved. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used, unless approved and documented. | Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that a graphical user interface is not installed with the following command: $ sudo dnf list --installed "xorg*common" Error: No matching Packages to list If the "x11-server-common" package is installed, and the use of a graphical user interface has not been documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Document the requirement for a graphical user interface with the ISSO or remove all xorg packages with the following command: Warning: If you are accessing the system through the graphical user interface, change to the multi-user.target with the following command: $ sudo systemctl isolate multi-user.target Warning: Removal of the graphical user interface will immediately render it useless. The following commands must not be run from a virtual terminal emulator in the graphical interface. $ sudo dnf remove "xorg*" $ sudo systemctl set-default multi-user.target |
CAT II | |||||
| 221 | CCI-000366 | SRG-OS-000480-GPOS-00227 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Red Hat Enterprise Linux 9 must use encryption for NTP communications. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | Verify that Red Hat Enterprise Linux 9 uses encryption for NTP communications. $ sudo grep nts /etc/ntp.conf /etc/chrony.conf server [ntp.server.name] iburst maxpoll 10 nts If "nts" is commented out or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use encryption for NTP communications. server [ntp.server.name] iburst maxpoll 10 nts |
CAT II | |||||||
| 222 | CCI-000366 | SRG-OS-000480-GPOS-00227 | The operating system must be configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. | Configuring the operating system to implement organization-wide security implementation guides and security checklists ensures compliance with federal standards and establishes a common security baseline across DoD that reflects the most restrictive security posture consistent with operational requirements. Configuration settings are the set of parameters that can be changed in hardware, software, or firmware components of the system that affect the security posture and/or functionality of the system. Security-related parameters are those parameters impacting the security state of the system, including the parameters required to satisfy other security control requirements. Security-related parameters include, for example: registry settings; account, file, directory permission settings; and settings for functions, ports, protocols, services, and remote connections. |
Applicable - Configurable | Verify the operating system is configured in accordance with the security configuration settings based on DoD security configuration or implementation guidance, including STIGs, NSA configuration guides, CTOs, and DTMs. If it is not, this is a finding. | CAT II | ||||||||||
| 223 | CCI-002617 | SRG-OS-000437-GPOS-00194 | CCE-83458-0 | The operating system must remove all software components after updated versions have been installed. | Red Hat Enterprise Linux 9 must remove all software components after updated versions have been installed. | Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Some information technology products may remove older versions of software automatically from the information system. | Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries. | Applicable - Configurable | Verify the operating system removes all software components after updated versions have been installed. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 removes all software components after updated versions have been installed with the following command: $ grep clean /etc/dnf/dnf.conf clean_requirements_on_remove=1 If "clean_requirements_on_remove" is not set to "1", this is a finding. |
Configure Red Hat Enterprise Linux 9 to remove all software components after updated versions have been installed. Edit the file /etc/dnf/dnf.conf by adding or editing the following line: clean_requirements_on_remove=1 |
CAT II | |||||
| 224 | CCI-002470 | SRG-OS-000403-GPOS-00182 | The operating system must only allow the use of DoD PKI-established certificate authorities for authentication in the establishment of protected sessions to the operating system. | Red Hat Enterprise Linux 9 must only allow the use of DoD PKI-established certificate authorities for authentication in the establishment of protected sessions to the operating system. | Untrusted Certificate Authorities (CA) can issue certificates, but they may be issued by organizations or individuals that seek to compromise DoD systems or by organizations with insufficient security controls. If the CA used for verifying the certificate is not a DoD-approved CA, trust of this CA has not been established. The DoD will only accept PKI-certificates obtained from a DoD-approved internal or external certificate authority. Reliance on CAs for the establishment of secure sessions includes, for example, the use of SSL/TLS certificates. |
Untrusted Certificate Authorities (CA) can issue certificates, but they may be issued by organizations or individuals that seek to compromise DoD systems or by organizations with insufficient security controls. If the CA used for verifying the certificate is not a DoD-approved CA, trust of this CA has not been established. The DoD will only accept PKI-certificates obtained from a DoD-approved internal or external certificate authority. Reliance on CAs for the establishment of secure sessions includes, for example, the use of SSL/TLS certificates. |
Applicable - Does Not Meet | Verify the operating system only allows the use of DoD PKI-established certificate authorities for verification of the establishment of protected sessions. If it does not, this is a finding. | Red Hat Enterprise Linux 9 does not support this requirement. This is an applicable-does not meet finding. | This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. | CAT II | This item can be mitigated by installing an additional packages/software that is not included in the default install of Red Hat Enterprise Linux 9. Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
This is a procedural-only requirement that is not enforced by the OS. | ||||
| 225 | CCI-000803,CCI-004062 | SRG-OS-000073-GPOS-00041,SRG-OS-000120-GPOS-00061 | CCE-89983-1 | The operating system must use mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. | Red Hat Enterprise Linux 9 must employ FIPS 140-3 approved cryptographic hashing algorithms for all stored passwords. | Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system. |
The system must use a strong hashing algorithm to store the password. Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. |
Applicable - Configurable | Verify the operating system uses mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. If it does not, this is a finding. | Verify that the interactive user account passwords are using a strong password hash with the following command: $ sudo cut -d: -f2 /etc/shadow $6$kcOnRq/5$NUEYPuyL.wghQwWssXRcLRFiiru7f5JPV6GaJhNC2aK5F3PZpE/BCCtwrxRc/AInKMNX3CdMw11m9STiql12f/ Password hashes "!" or "*" indicate inactive accounts not available for logon and are not evaluated. If any interactive user password hash does not begin with "$6", this is a finding. |
Lock all interactive user accounts not using SHA-512 hashing until the passwords can be regenerated with SHA-512. | CAT II | |||||
| 226 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-90319-5 | The operating system must use mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. | Red Hat Enterprise Linux 9 must not have unauthorized IP tunnels configured. | Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system. |
IP tunneling mechanisms can be used to bypass network filtering. If tunneling is required, it must be documented with the information system security officer (ISSO). | Applicable - Configurable | Verify the operating system uses mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 does not have unauthorized IP tunnels configured. Determine if the "IPsec" service is active with the following command: $ systemctl status ipsec ipsec.service - Internet Key Exchange (IKE) Protocol Daemon for IPsec Loaded: loaded (/usr/lib/systemd/system/ipsec.service; disabled) Active: inactive (dead) If the "IPsec" service is active, check for configured IPsec connections ("conn"), with the following command: $ grep -rni conn /etc/ipsec.conf /etc/ipsec.d/ Verify any returned results are documented with the ISSO. If the IPsec tunnels are active and not approved, this is a finding. |
Remove all unapproved tunnels from the system, or document them with the ISSO. | CAT II | |||||
| 227 | CCI-004062 | SRG-OS-000073-GPOS-00041,SRG-OS-000120-GPOS-00061 | CCE-85946-2 | The operating system must use mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. | Red Hat Enterprise Linux 9 pam_unix.so module must be configured in the password-auth file to use a FIPS 140-3 approved cryptographic hashing algorithm for system authentication. | Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system. |
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and; therefore, cannot be relied upon to provide confidentiality or integrity, and DOD data may be compromised. Red Hat Enterprise Linux 9 systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system. |
Applicable - Configurable | Verify the operating system uses mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. If it does not, this is a finding. | Verify that the pam_unix.so module is configured to use sha512 in /etc/pam.d/password-auth with the following command: $ grep "^password.*pam_unix.so.*sha512" /etc/pam.d/password-auth password sufficient pam_unix.so sha512 If "sha512" is missing, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use a FIPS 140-3 approved cryptographic hashing algorithm for system authentication. Edit/modify the following line in the "/etc/pam.d/password-auth" file to include the sha512 option for pam_unix.so: password sufficient pam_unix.so sha512 |
CAT II | |||||
| 228 | CCI-000196,CCI-000803,CCI-004062 | SRG-OS-000073-GPOS-00041,SRG-OS-000120-GPOS-00061 | CCE-83581-9 | The operating system must use mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. | Red Hat Enterprise Linux 9 pam_unix.so module must be configured in the password-auth file to use a FIPS 140-3 approved cryptographic hashing algorithm for system authentication. | Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2/140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general purpose computing system. |
Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and therefore cannot be relied upon to provide confidentiality or integrity, and DoD data may be compromised. Red Hat Enterprise Linux 9 systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets DoD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system. |
Applicable - Configurable | Verify the operating system uses mechanisms meeting the requirements of applicable federal laws, Executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. If it does not, this is a finding. | Verify that the pam_unix.so module is configured to use sha512 in /etc/pam.d/password-auth with the following command: $ grep "^password.*pam_unix.so.*sha512" /etc/pam.d/password-auth password sufficient pam_unix.so sha512 If "sha512" is missing, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use a FIPS 140-3 approved cryptographic hashing algorithm for system authentication. Edit/modify the following line in the "/etc/pam.d/password-auth" file to include the sha512 option for pam_unix.so: password sufficient pam_unix.so sha512 |
CAT II | |||||
| 229 | CCI-000163,CCI-000164,CCI-001314,CCI-000162 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-OS-000206-GPOS-00084 | CCE-90516-6 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 audit logs must be group-owned by root or by a restricted logging group to prevent unauthorized read access. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. | Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the audit logs are group-owned by "root" or a restricted logging group. First determine if a group other than "root" has been assigned to the audit logs with the following command: $ sudo grep log_group /etc/audit/auditd.conf Then determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Then using the location of the audit log file, determine if the audit log is group-owned by "root" using the following command: $ sudo stat -c "%G %n" /var/log/audit/audit.log root /var/log/audit/audit.log If the audit log is not group-owned by "root" or the configured alternative logging group, this is a finding. |
Change the group of the directory of "/var/log/audit" to be owned by a correct group. Identify the group that is configured to own audit log: $ sudo grep -P '^[ ]*log_group[ ]+=.*$' /etc/audit/auditd.conf Change the ownership to that group: $ sudo chgrp ${GROUP} /var/log/audit |
CAT II | |||||
| 230 | CCI-000163,CCI-000164,CCI-001314,CCI-000162 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-OS-000206-GPOS-00084 | CCE-85869-6 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 audit log directory must be owned by root to prevent unauthorized read access. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. | Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the audit logs directory is owned by "root". First determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Then using the location of the audit log file, determine if the audit log directory is owned by "root" using the following command: $ sudo ls -ld /var/log/audit drwx------ 2 root root 23 Jun 11 11:56 /var/log/audit If the audit log directory is not owned by "root", this is a finding. |
Configure the audit log to be protected from unauthorized read access by setting the correct owner as "root" with the following command: $ sudo chown root /var/log/audit |
CAT II | |||||
| 231 | CCI-000162,CCI-000163,CCI-000164,CCI-001314 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-OS-000206-GPOS-00084 | CCE-89603-5 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 audit log files must be group-owned by root or a restricted logging group to prevent unauthorized access. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Check group owners of the system audit logs. First, determine where the audit log file is located. $ sudo grep -iw ^log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log The log_file option specifies the audit log file path. If the log_file option isn't defined, check all files within /var/log/audit directory. Then, determine the audit log group by running the following command: $ sudo grep -P '^[ ]*log_group[ ]+=.*$' /etc/audit/auditd.conf Then, check that the audit log file is owned by the correct group. Run the following command to display the owner of the audit log file: $ sudo stat -c "%n %G" "log_file" The audit log file must be owned by the log_group or by root if the log_group is not specified. If audit log files are owned by incorrect group, then this is a finding. |
Change the group of the audit log file to be owned by a correct group. Identify where the audit log file is located: $ sudo grep -iw ^log_file /etc/audit/auditd.conf Identify the group that is configured to own audit log: $ sudo grep -P '^[ ]*log_group[ ]+=.*$' /etc/audit/auditd.conf Change the ownership to that group: $ sudo chgrp ${log_group} ${log_file} |
CAT II | |||||
| 232 | CCI-000162,CCI-000163,CCI-000164,CCI-001314 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-OS-000206-GPOS-00084 | CCE-89952-6 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 audit logs must be owned by the root to prevent unauthorized access. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. | Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the audit logs are owned by "root". First determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Then using the location of the audit log file, determine if the audit log files are owned by "root" using the following command: $ sudo ls -la /var/log/audit/*.log rw-------. 2 root root 237923 Jun 11 11:56 /var/log/audit/audit.log If the audit logs are not owned by "root", this is a finding. |
Configure the audit logs owner as "root" with the following command: $ sudo chown root [audit_log_file] Replace "[audit_log_file]" to the correct audit log path, by default this location is "/var/log/audit/audit.log". |
CAT II | |||||
| 233 | CCI-000163,CCI-000164,CCI-001314,CCI-000162 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-OS-000206-GPOS-00084,SRG-APP-000118-CTR-000240 | CCE-83720-3 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 audit logs file must have mode 0600 or less permissive to prevent unauthorized access to the audit log. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the audit logs have a mode of "0600". First determine where the audit logs are stored with the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Then using the location of the audit log file, determine if the audit log files as a mode of "0640" with the following command: $ sudo ls -la /var/log/audit/*.log rw-------. 2 root root 237923 Jun 11 11:56 /var/log/audit/audit.log If the audit logs have a mode more permissive than "0600", this is a finding. |
Configure the audit logs to have a mode of "0600" with the following command: Replace "[audit_log_file]" to the correct audit log path, by default this location is "/var/log/audit/audit.log". $ sudo chmod 0600 /var/log/audit/[audit_log_file] Check the group that owns the system audit logs: $ sudo grep -m 1 -q ^log_group /etc/audit/auditd.conf If the log_group is not defined or it is set to root, configure the permissions the following way: $ sudo chmod 0640 $log_file $ sudo chmod 0440 $log_file.* Otherwise, configure the permissions the following way: $ sudo chmod 0600 $log_file $ sudo chmod 0400 $log_file.* |
CAT II | |||||
| 234 | CCI-001314 | SRG-OS-000206-GPOS-00084,SRG-APP-000118-CTR-000240 | CCE-83912-6 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log directory must be group-owned by root. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the "/var/log" directory is group-owned by root with the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have a group owner of "root", this is a finding. |
Configure the group owner of the directory "/var/log" to "root" by running the following command: $ sudo chgrp root /var/log |
CAT II | |||||
| 235 | CCI-001314 | SRG-OS-000206-GPOS-00084 | CCE-83916-7 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log/messages file must be group-owned by root. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the "/var/log/messages" file is group-owned by root with the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have a group owner of "root", this is a finding. |
Change the group owner of the "/var/log/messages" file to "root" by running the following command: $ sudo chgrp root /var/log/messages |
CAT II | |||||
| 236 | CCI-001314 | SRG-OS-000206-GPOS-00084,SRG-APP-000118-CTR-000240 | CCE-83914-2 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log directory must be owned by root. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the "/var/log" directory is owned by root with the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have an owner of "root", this is a finding. |
Configure the owner of the directory "/var/log" to "root" by running the following command: $ sudo chown root /var/log |
CAT II | |||||
| 237 | CCI-001314 | SRG-OS-000206-GPOS-00084 | CCE-83915-9 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log/messages file must be owned by root. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the "/var/log/messages" file is owned by root with the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have an owner of "root", this is a finding. |
Change the owner of the "/var/log/messages" file to "root" by running the following command: $ sudo chown root /var/log/messages |
CAT II | |||||
| 238 | CCI-001314 | SRG-OS-000206-GPOS-00084,SRG-APP-000118-CTR-000240 | CCE-83917-5 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log directory must have mode 0755 or less permissive. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify that the "/var/log" directory has a mode of "0755" or less permissive with the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have a mode of "0755" or less permissive, this is a finding. |
Configure the "/var/log" directory to a mode of "0755" by running the following command: $ sudo chmod 0755 /var/log |
CAT II | |||||
| 239 | CCI-001314 | SRG-OS-000206-GPOS-00084 | CCE-83913-4 | The operating system must reveal error messages only to authorized users. | Red Hat Enterprise Linux 9 /var/log/messages file must have mode 0640 or less permissive. | Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the operating system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the Red Hat Enterprise Linux 9 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. |
Applicable - Configurable | Verify the operating system reveals error messages only to authorized users. If it does not, this is a finding. | Verify the "/var/log/messages" file has a mode of "0640" or less permissive with the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have a mode of "0640" or less permissive, this is a finding. |
Configure the "/var/log/messages" file to have a mode of "0640" by running the following command: $ sudo chmod 0640 /var/log/messages |
CAT II | |||||
| 240 | CCI-000186 | SRG-OS-000067-GPOS-00035 | CCE-86553-5 | The operating system, for PKI-based authentication, must enforce authorized access to the corresponding private key. | Red Hat Enterprise Linux 9, for PKI-based authentication, must enforce authorized access to the corresponding private key. | If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and non-repudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys. |
If the private key is discovered, an attacker can use the key to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and nonrepudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys. |
Applicable - Configurable | Verify the operating system, for PKI-based authentication, enforces authorized access to the corresponding private key. If it does not, this is a finding. | Verify the SSH private key files have a passcode. For each private key stored on the system, use the following command: $ sudo ssh-keygen -y -f /path/to/file If the contents of the key are displayed, this is a finding. If the contents of the key are displayed, this is a finding. |
Create a new private and public key pair that utilizes a passcode with the following command: $ sudo ssh-keygen -n [passphrase] |
CAT II | |||||
| 241 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000471-GPOS-00216,SRG-OS-000477-GPOS-00222,SRG-APP-000495-CTR-001235,SRG-APP-000504-CTR-001280 | CCE-83802-9 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Red Hat Enterprise Linux 9 must audit all uses of the delete_module system call. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "delete_module" system call with the following command: $ sudo auditctl -l | grep delete_module -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng If both the "b32" and "b64" audit rules are not defined for the "delete_module" system call, or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate an audit event for any successful/unsuccessful use of the "delete_module" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 242 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000471-GPOS-00216,SRG-OS-000477-GPOS-00222,SRG-APP-000495-CTR-001235,SRG-APP-000504-CTR-001280 | CCE-83803-7 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Red Hat Enterprise Linux 9 must audit all uses of the init_module and finit_module system calls. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "init_module" and "finit_module" syscalls with the following command: $ sudo auditctl -l | grep init_module -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng If both the "b32" and "b64" audit rules are not defined for the "delete_module" syscall, or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate an audit event for any successful/unsuccessful use of the "init_module" and "finit_module" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 243 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000471-GPOS-00216,SRG-OS-000477-GPOS-00222,SRG-APP-000495-CTR-001235,SRG-APP-000504-CTR-001280 | CCE-90835-0 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Red Hat Enterprise Linux 9 Must Provide Audit Record Generation Capability For Dod-Defined Auditable Events For All Operating System Components. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
The addition of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel. |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | To determine if the system is configured to audit calls to the init_module system call, run the following command: $ sudo grep "init_module" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
CAT II | ||||||
| 244 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000471-GPOS-00216,SRG-OS-000477-GPOS-00222,SRG-APP-000495-CTR-001235,SRG-APP-000504-CTR-001280 | CCE-90262-7 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Red Hat Enterprise Linux 9 must audit all uses of the kmod command. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "kmod" command with the following command: $ sudo auditctl -l | grep kmod -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -k modules If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "kmod" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -k modules The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 245 | CCI-000130,CCI-000169,CCI-000172,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | CAT II | ||||||||||
| 246 | CCI-000130,CCI-000169,CCI-000172,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | CAT II | ||||||||||
| 247 | CCI-000172 | SRG-OS-000477-GPOS-00222 | CCE-85956-1 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Successful/unsuccessful uses of the init command in Red Hat Enterprise Linux 9 must generate an audit record. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Misuse of the init command may cause availability issues for the system. | Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "init" command with the following command: $ sudo auditctl -l | grep init -a always,exit -F path=/usr/sbin/init -F perm=x -F auid>=1000 -F auid!=unset -k privileged-init If the command does not return a line, or the line is commented out, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful uses of the "init" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/init -F perm=x -F auid>=1000 -F auid!=unset -k privileged-init The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 248 | CCI-000172 | SRG-OS-000477-GPOS-00222 | CCE-85957-9 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Successful/unsuccessful uses of the poweroff command in Red Hat Enterprise Linux 9 must generate an audit record. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Misuse of the poweroff command may cause availability issues for the system. | Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "poweroff" command with the following command: $ sudo auditctl -l | grep poweroff -a always,exit -F path=/usr/sbin/poweroff -F perm=x -F auid>=1000 -F auid!=unset -k privileged-poweroff If the command does not return a line, or the line is commented out, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful uses of the "poweroff" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/poweroff -F perm=x -F auid>=1000 -F auid!=unset -k privileged-poweroff The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 249 | CCI-000172 | SRG-OS-000477-GPOS-00222 | CCE-85958-7 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Successful/unsuccessful uses of the reboot command in Red Hat Enterprise Linux 9 must generate an audit record. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Misuse of the reboot command may cause availability issues for the system. | Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "reboot" command with the following command: $ sudo auditctl -l | grep reboot -a always,exit -F path=/usr/sbin/reboot -F perm=x -F auid>=1000 -F auid!=unset -k privileged-reboot If the command does not return a line, or the line is commented out, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful uses of the "reboot" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/reboot -F perm=x -F auid>=1000 -F auid!=unset -k privileged-reboot The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 250 | CCI-000172 | SRG-OS-000477-GPOS-00222 | CCE-85959-5 | The operating system must generate audit records for all kernel module load, unload, and restart actions, and also for all program initiations. | Successful/unsuccessful uses of the shutdown command in Red Hat Enterprise Linux 9 must generate an audit record. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Misuse of the shutdown command may cause availability issues for the system. | Applicable - Configurable | Verify the operating system generates audit records for all kernel module load, unload, and restart actions, and also for all program initiations. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "shutdown" command with the following command: $ sudo auditctl -l | grep shutdown -a always,exit -F path=/usr/sbin/shutdown -F perm=x -F auid>=1000 -F auid!=unset -k privileged-shutdown If the command does not return a line, or the line is commented out, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful uses of the "shutdown" command by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/shutdown -F perm=x -F auid>=1000 -F auid!=unset -k privileged-shutdown The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 251 | CCI-000016,CCI-001682 | SRG-OS-000123-GPOS-00064,SRG-OS-000002-GPOS-00002 | CCE-90096-9 | The information system must automatically remove or disable emergency accounts after the crisis is resolved or 72 hours. | Red Hat Enterprise Linux 9 must automatically expire temporary accounts within 72 hours. | Emergency accounts are privileged accounts that are established in response to crisis situations where the need for rapid account activation is required. Therefore, emergency account activation may bypass normal account authorization processes. If these accounts are automatically disabled, system maintenance during emergencies may not be possible, thus adversely affecting system availability. Emergency accounts are different from infrequently used accounts (i.e., local logon accounts used by the organization's system administrators when network or normal logon/access is not available). Infrequently used accounts are not subject to automatic termination dates. Emergency accounts are accounts created in response to crisis situations, usually for use by maintenance personnel. The automatic expiration or disabling time period may be extended as needed until the crisis is resolved; however, it must not be extended indefinitely. A permanent account should be established for privileged users who need long-term maintenance accounts. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements. |
Temporary accounts are privileged or nonprivileged accounts that are established during pressing circumstances, such as new software or hardware configuration or an incident response, where the need for prompt account activation requires bypassing normal account authorization procedures. If any inactive temporary accounts are left enabled on the system and are not either manually removed or automatically expired within 72 hours, the security posture of the system will be degraded and exposed to exploitation by unauthorized users or insider threat actors. Temporary accounts are different from emergency accounts. Emergency accounts, also known as "last resort" or "break glass" accounts, are local logon accounts enabled on the system for emergency use by authorized system administrators to manage a system when standard logon methods are failing or not available. Emergency accounts are not subject to manual removal or scheduled expiration requirements. The automatic expiration of temporary accounts may be extended as needed by the circumstances but it must not be extended indefinitely. A documented permanent account should be established for privileged users who need long-term maintenance accounts. |
Applicable - Configurable | Verify the operating system is configured such that emergency administrator accounts are automatically removed or disabled within 72 hours. If it is not, this is a finding. | Verify temporary accounts have been provisioned with an expiration date of 72 hours. For every existing temporary account, run the following command to obtain its account expiration information: $ sudo chage -l <temporary_account_name> | grep -i "account expires" Verify each of these accounts has an expiration date set within 72 hours. If any temporary accounts have no expiration date set or do not expire within 72 hours, this is a finding. |
Configure the operating system to expire temporary accounts after 72 hours with the following command: $ sudo chage -E $(date -d +3days +%Y-%m-%d) <temporary_account_name> |
CAT II | |||||
| 252 | CCI-001774,CCI-001764 | SRG-OS-000370-GPOS-00155,SRG-OS-000368-GPOS-00154,SRG-OS-000480-GPOS-00230 | CCE-84224-5 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 fapolicy module must be installed. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting. Utilizing an allowlist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of allowlisted software occurs prior to execution or at system startup. User home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any sharing of information with an SA through shared resources. Red Hat Enterprise Linux 9 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". "fapolicyd" is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blocklist or allowlist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system nonfunctional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 fapolicyd package is installed with the following command: $ sudo dnf list --installed fapolicyd Example output: fapolicyd.x86_64 1.1-103.el9_0 If the "fapolicyd" package is not installed, this is a finding. |
The fapolicyd package can be installed with the following command: $ sudo dnf install fapolicyd |
CAT II | |||||
| 253 | CCI-001774,CCI-001764 | SRG-OS-000370-GPOS-00155,SRG-OS-000368-GPOS-00154,SRG-OS-000480-GPOS-00230 | CCE-84227-8 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 fapolicy module must be enabled. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting. Utilizing an allowlist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of allowlisted software occurs prior to execution or at system startup. User home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any sharing of information with an SA through shared resources. Red Hat Enterprise Linux 9 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". "fapolicyd" is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blocklist or allowlist processes or file access. Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system nonfunctional. The "fapolicyd" API is not namespace aware and can cause issues when launching or running containers. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 fapolicyd is active with the following command: $ systemctl is-active fapolicyd active If fapolicyd module is not active, this is a finding. |
Enable the fapolicyd with the following command: $ systemctl enable --now fapolicyd |
CAT II | |||||
| 254 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83884-7 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /boot with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The only legitimate location for device files is the "/dev" directory located on the root partition. The only exception to this is chroot jails. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify that the "/boot" mount point has the "nodev" option is with the following command: Note: This control is not applicable to Red Hat Enterprise Linux 9 system booted UEFI. $ sudo mount | grep '\s/boot\s' /dev/sda1 on /boot type xfs (rw,nodev,relatime,seclabel,attr2) If the "/boot" file system does not have the "nodev" option set, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/boot" directory. | CAT II | |||||
| 255 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83881-3 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /dev/shm with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/dev/shm" is mounted with the "nodev" option with the following command: $ mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the /dev/shm file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/dev/shm" file system. | CAT II | |||||
| 256 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83857-3 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /dev/shm with the noexec option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/dev/shm" is mounted with the "noexec" option with the following command: $ mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the /dev/shm file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/dev/shm" file system. | CAT II | |||||
| 257 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83891-2 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /dev/shm with the nosuid option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/dev/shm" is mounted with the "nosuid" option with the following command: $ mount | grep /dev/shm tmpfs on /dev/shm type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the /dev/shm file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/dev/shm" file system. | CAT II | |||||
| 258 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83871-4 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must prevent device files from being interpreted on file systems that contain user home directories. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/home" is mounted with the "nodev" option with the following command: Note: If a separate file system has not been created for the user home directories (user home directories are mounted under "/"), this is automatically a finding, as the "nodev" option cannot be used on the "/" system. $ mount | grep /home tmpfs on /home type tmpfs (rw,nodev,nosuid,noexec,seclabel) If the "/home" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/home" directory. | CAT II | |||||
| 259 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83869-8 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /tmp with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/tmp" is mounted with the "nodev" option: $ mount | grep /tmp /dev/mapper/rhel-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/tmp" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/tmp" directory. | CAT II | |||||
| 260 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83885-4 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /tmp with the noexec option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/tmp" is mounted with the "noexec" option: $ mount | grep /tmp /dev/mapper/rhel-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/tmp" file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/tmp" directory. | CAT II | |||||
| 261 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83872-2 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /tmp with the nosuid option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/tmp" is mounted with the "nosuid" option: $ mount | grep /tmp /dev/mapper/rhel-tmp on /tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/tmp" file system is mounted without the "nosuid" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/tmp" directory. | CAT II | |||||
| 262 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83882-1 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log/audit with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log/audit" is mounted with the "nodev" option: $ mount | grep /var/log/audit /dev/mapper/rhel-var-log-audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log/audit" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/var/log/audit" directory. | CAT II | |||||
| 263 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83878-9 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log/audit with the noexec option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log/audit" is mounted with the "noexec" option: $ mount | grep /var/log/audit /dev/mapper/rhel-var-log-audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log/audit" file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/var/log/audit" directory. | CAT II | |||||
| 264 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83893-8 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log/audit with the nosuid option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log/audit" is mounted with the "nosuid" option: $ mount | grep /var/log/audit /dev/mapper/rhel-var-log-audit on /var/log/audit type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log/audit" file system is mounted without the "nosuid" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/var/log/audit" directory. | CAT II | |||||
| 265 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83886-2 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log" is mounted with the "nodev" option: $ mount | grep /var/log /dev/mapper/rhel-var-log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/var/log" directory. | CAT II | |||||
| 266 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83887-0 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log with the noexec option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log" is mounted with the "noexec" option: $ mount | grep /var/log /dev/mapper/rhel-var-log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log" file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/var/log" directory. | CAT II | |||||
| 267 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83870-6 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/log with the nosuid option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/log" is mounted with the "nosuid" option: $ mount | grep /var/log /dev/mapper/rhel-var-log on /var/log type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/log" file system is mounted without the "nosuid" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/var/log" directory. | CAT II | |||||
| 268 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83868-0 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var" is mounted with the "nodev" option: $ mount | grep /var /dev/mapper/rhel-var on /var type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/var" directory. | CAT II | |||||
| 269 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83864-9 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/tmp with the nodev option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. The only legitimate location for device files is the "/dev" directory located on the root partition, with the exception of chroot jails if implemented. |
Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/tmp" is mounted with the "nodev" option: $ mount | grep /var/tmp /dev/mapper/rhel-var-tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/tmp" file system is mounted without the "nodev" option, this is a finding. |
Modify "/etc/fstab" to use the "nodev" option on the "/var/tmp" directory. | CAT II | |||||
| 270 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83866-4 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/tmp with the noexec option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "noexec" mount option causes the system to not execute binary files. This option must be used for mounting any file system not containing approved binary files, as they may be incompatible. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/tmp" is mounted with the "noexec" option: $ mount | grep /var/tmp /dev/mapper/rhel-var-tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/tmp" file system is mounted without the "noexec" option, this is a finding. |
Modify "/etc/fstab" to use the "noexec" option on the "/var/tmp" directory. | CAT II | |||||
| 271 | CCI-001764 | SRG-OS-000368-GPOS-00154 | CCE-83863-1 | The operating system must prevent program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. | Red Hat Enterprise Linux 9 must mount /var/tmp with the nosuid option. | Control of program execution is a mechanism used to prevent execution of unauthorized programs. Some operating systems may provide a capability that runs counter to the mission or provides users with functionality that exceeds mission requirements. This includes functions and services installed at the operating system-level. Some of the programs, installed by default, may be harmful or may not be necessary to support essential organizational operations (e.g., key missions, functions). Removal of executable programs is not always possible; therefore, establishing a method of preventing program execution is critical to maintaining a secure system baseline. Methods for complying with this requirement include restricting execution of programs in certain environments, while preventing execution in other environments; or limiting execution of certain program functionality based on organization-defined criteria (e.g., privileges, subnets, sandboxed environments, or roles). |
The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. | Applicable - Configurable | Verify the operating system prevents program execution in accordance with local policies regarding software program usage and restrictions and/or rules authorizing the terms and conditions of software program usage. If it does not, this is a finding. | Verify "/var/tmp" is mounted with the "nosuid" option: $ mount | grep /var/tmp /dev/mapper/rhel-var-tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/tmp" file system is mounted without the "nosuid" option, this is a finding. |
Modify "/etc/fstab" to use the "nosuid" option on the "/var/tmp" directory. | CAT II | |||||
| 272 | CCI-000159 | SRG-OS-000055-GPOS-00026 | The operating system must use internal system clocks to generate time stamps for audit records. | Red Hat Enterprise Linux 9 must use internal system clocks to generate time stamps for audit records. | Without an internal clock used as the reference for the time stored on each event to provide a trusted common reference for the time, forensic analysis would be impeded. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. If the internal clock is not used, the system may not be able to provide time stamps for log messages. Additionally, externally generated time stamps may not be accurate. |
Without an internal clock used as the reference for the time stored on each event to provide a trusted common reference for the time, forensic analysis would be impeded. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. If the internal clock is not used, the system may not be able to provide time stamps for log messages. Additionally, externally generated time stamps may not be accurate. |
Applicable - Inherently Met | Verify the operating system uses internal system clocks to generate time stamps for audit records. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
CAT II | The "ausearch" tool manpage describes how it can be used to search for audit records based on their associated timestamps: http://man7.org/linux/man-pages/man8/ausearch.8.html. | The default setup of "rsyslogd" uses timestamps and the default setup of "chronyd" uses the system clock. | ||||
| 273 | CCI-000172,CCI-002884 | SRG-OS-000392-GPOS-00172,SRG-OS-000470-GPOS-00214,SRG-OS-000473-GPOS-00218,SRG-APP-000503-CTR-001275,SRG-APP-000506-CTR-001290 | CCE-83783-1 | The operating system must generate audit records when concurrent logons to the same account occur from different sources. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/faillock. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Applicable - Configurable | Verify the operating system generates audit records when concurrent logons to the same account occur from different sources. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/faillock" with the following command: $ sudo auditctl -l | grep /var/log/faillock -w /var/log/faillock -p wa -k logins If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/faillock". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/faillock -p wa -k logins The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 274 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000473-GPOS-00218,SRG-OS-000470-GPOS-00214,SRG-APP-000495-CTR-001235,SRG-APP-000503-CTR-001275,SRG-APP-000506-CTR-001290 | CCE-83785-6 | The operating system must generate audit records when concurrent logons to the same account occur from different sources. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/lastlog. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Applicable - Configurable | Verify the operating system generates audit records when concurrent logons to the same account occur from different sources. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/lastlog" with the following command: $ sudo auditctl -l | grep /var/log/lastlog -w /var/log/lastlog -p wa -k logins If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/lastlog". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/lastlog -p wa -k logins The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 275 | CCI-000172,CCI-002884 | SRG-OS-000392-GPOS-00172,SRG-OS-000470-GPOS-00214,SRG-OS-000473-GPOS-00218,SRG-APP-000503-CTR-001275 | CCE-83782-3 | The operating system must generate audit records when concurrent logons to the same account occur from different sources. | Red Hat Enterprise Linux 9 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/tallylog. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. | Applicable - Configurable | Verify the operating system generates audit records when concurrent logons to the same account occur from different sources. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/tallylog" with the following command: $ sudo auditctl -l | grep /var/log/tallylog -w /var/log/tallylog -p wa -k logins If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/tallylog". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/tallylog -p wa -k logins The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 276 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884,CCI-001464 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000473-GPOS-00218,SRG-OS-000254-GPOS-00095 | CCE-83651-0 | The operating system must generate audit records when concurrent logons to the same account occur from different sources. | Red Hat Enterprise Linux 9 must enable auditing of processes that start prior to the audit daemon. | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). |
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. |
Applicable - Configurable | Verify the operating system generates audit records when concurrent logons to the same account occur from different sources. If it does not, this is a finding. | Verify that GRUB 2 is configured to enable auditing of processes that start prior to the audit daemon with the following commands: Check that the current GRUB 2 configuration enabled auditing: $ sudo grubby --info=ALL | grep audit args="ro crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on If "audit" is not set to "1" or is missing, this is a finding. Check that auditing is enabled by default to persist in kernel updates: $ sudo grep audit /etc/default/grub GRUB_CMDLINE_LINUX="audit=1" If "audit" is not set to "1", is missing, or is commented out, this is a finding. |
Enable auditing of processes that start prior to the audit daemon with the following command: $ sudo grubby --update-kernel=ALL --args="audit=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="audit=1" |
CAT II | |||||
| 277 | CCI-001890,CCI-004926,CCI-004923 | SRG-OS-000355-GPOS-00143,SRG-OS-000356-GPOS-00144,SRG-OS-000359-GPOS-00146 | CCE-88648-1 | The operating system must synchronize internal information system clocks to the authoritative time source when the time difference is greater than one second. | Red Hat Enterprise Linux 9 must securely compare internal information system clocks at least every 24 hours with a server synchronized to an authoritative time source, such as the United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider setting time periods for different types of systems (e.g., financial, legal, or mission-critical systems). Organizations should also consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). This requirement is related to the comparison done every 24 hours in SRG-OS-000355 because a comparison must be done in order to determine the time difference. |
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. |
Applicable - Configurable | Verify the operating system synchronizes internal information system clocks to the authoritative time source when the time difference is greater than one second. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is securely comparing internal information system clocks at a regular interval with an NTP server with the following command: $ sudo grep maxpoll /etc/ntp.conf /etc/chrony.conf server [ntp.server.name] iburst maxpoll 10 If "maxpoll" has not been set to the of "10", is commented out, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to securely compare internal information system clocks at a regular interval with an NTP server by adding/modifying the following line in the /etc/chrony.conf file. server [ntp.server.name] iburst maxpoll 10 |
CAT II | |||||
| 278 | CCI-000169 | SRG-OS-000062-GPOS-00031,SRG-OS-000471-GPOS-00215,SRG-APP-000141-CTR-000315 | CCE-84206-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must enable Linux audit logging for the USBGuard daemon. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DOD has defined the list of events for which Red Hat Enterprise Linux 9 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To verify that Linux Audit logging is enabled for the USBGuard daemon with the following command: $ sudo grep AuditBackend /etc/usbguard/usbguard-daemon.conf AuditBackend=LinuxAudit If "AuditBackend" is not set to "LinuxAudit", this is a finding. |
Configure Red Hat Enterprise Linux 9 USBGuard AuditBackend to use the audit system. Add or edit the following line in /etc/usbguard/usbguard-daemon.conf AuditBackend=LinuxAudit |
CAT II | |||||
| 279 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83830-0 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chmod, fchmod, and fchmodat syscalls. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chmod", "fchmod", and "fchmodat" syscalls with the following command: $ sudo auditctl -l | grep chmod -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chmod", "fchmod", and "fchmodat" syscalls, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chmod", "fchmod", and "fchmodat" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 280 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-OS-000474-GPOS-00219,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83812-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chown, fchown, fchownat, and lchown syscalls. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chown", "fchown", "fchownat", and "lchown" syscalls with the following command: $ sudo auditctl -l | grep chown -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chown", "fchown", "fchownat", and "lchown" syscalls, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chown", "fchown", "fchownat", and "lchown"" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 281 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83832-6 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the fchmod system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the fchmod system call, run the following command: $ sudo grep "fchmod" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchmod" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "chmod", "fchmod" and "fchmodat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 282 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83822-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the fchmodat system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the fchmodat system call, run the following command: $ sudo grep "fchmodat" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchmodat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "chmod", "fchmod" and "fchmodat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 283 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-OS-000474-GPOS-00219,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83829-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the fchown system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the fchown system call, run the following command: $ sudo grep "fchown" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchown" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "chown", "fchown", "fchownat" and "lchown". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 284 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-OS-000474-GPOS-00219,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83831-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the fchownat system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the fchownat system call, run the following command: $ sudo grep "fchownat" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fchownat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "chown", "fchown", "fchownat" and "lchown". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 285 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000462-GPOS-00206,SRG-OS-000463-GPOS-00207,SRG-OS-000471-GPOS-00215,SRG-OS-000474-GPOS-00219,SRG-OS-000466-GPOS-00210,SRG-OS-000468-GPOS-00212,SRG-OS-000064-GPOS-00033,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000499-CTR-001255 | CCE-83821-9 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls with the following command: $ sudo auditctl -l | grep xattr -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chmod", "fchmod", and "fchmodat" syscalls "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" ssytem calls, or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 286 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000462-GPOS-00206,SRG-OS-000463-GPOS-00207,SRG-OS-000466-GPOS-00210,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-OS-000474-GPOS-00219,SRG-OS-000064-GPOS-00033,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83817-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the fsetxattr system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the fsetxattr system call, run the following command: $ sudo grep "fsetxattr" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "fsetxattr" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "fremovexattr", "lremovexattr", "removexattr", "fsetxattr", "lsetxattr" and "setxattr". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 287 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000466-GPOS-00210,SRG-OS-000458-GPOS-00203,SRG-OS-000474-GPOS-00219,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-83833-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the lchown system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the lchown system call, run the following command: $ sudo grep "lchown" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "lchown" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "chown", "fchown", "fchownat" and "lchown". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 288 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000462-GPOS-00206,SRG-OS-000463-GPOS-00207,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-OS-000474-GPOS-00219,SRG-OS-000466-GPOS-00210,SRG-OS-000064-GPOS-00033,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83814-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the lremovexattr system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the lremovexattr system call, run the following command: $ sudo grep "lremovexattr" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "lremovexattr" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "fremovexattr", "lremovexattr", "removexattr", "fsetxattr", "lsetxattr" and "setxattr". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 289 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000462-GPOS-00206,SRG-OS-000463-GPOS-00207,SRG-OS-000466-GPOS-00210,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-OS-000474-GPOS-00219,SRG-OS-000064-GPOS-00033,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83808-6 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the lsetxattr system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the lsetxattr system call, run the following command: $ sudo grep "lsetxattr" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "lsetxattr" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "fremovexattr", "lremovexattr", "removexattr", "fsetxattr", "lsetxattr" and "setxattr". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 290 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000462-GPOS-00206,SRG-OS-000463-GPOS-00207,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-OS-000474-GPOS-00219,SRG-OS-000466-GPOS-00210,SRG-OS-000064-GPOS-00033,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83807-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the removexattr system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the removexattr system call, run the following command: $ sudo grep "removexattr" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "removexattr" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "fremovexattr", "lremovexattr", "removexattr", "fsetxattr", "lsetxattr" and "setxattr". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 291 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000466-GPOS-00210,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-APP-000091-CTR-000160,SRG-APP-000492-CTR-001220,SRG-APP-000493-CTR-001225,SRG-APP-000494-CTR-001230,SRG-APP-000500-CTR-001260,SRG-APP-000507-CTR-001295,SRG-APP-000495-CTR-001235 | CCE-83811-0 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the setxattr system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the setxattr system call, run the following command: $ sudo grep "setxattr" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "setxattr" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -k perm_mod It's allowed to group this system call within the same line as "fremovexattr", "lremovexattr", "removexattr", "fsetxattr", "lsetxattr" and "setxattr". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 292 | CCI-000172,CCI-000130,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-89272-9 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the umount system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. | Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 generates an audit record for all uses of the "umount" and system call with the following command: $ sudo grep "umount" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line like the following: -a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=unset -k privileged-umount If the command does not return a line, or the line is commented out, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory: -a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=unset -k privileged-umount The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 293 | CCI-000172,CCI-000130,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-88570-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the umount2 system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. | Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the umount2 system call, run the following command: $ sudo grep "umount2" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount2" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory: -a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 294 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-87685-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chacl command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chacl" command with the following command: $ sudo auditctl -l | grep chacl -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chacl" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 295 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-90482-1 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the setfacl command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "setfacl" command with the following command: $ sudo auditctl -l | grep setfacl -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "setfacl" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 296 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-OS-000463-GPOS-00207,SRG-OS-000465-GPOS-00209,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83748-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chcon command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chcon" command with the following command: $ sudo auditctl -l | grep chcon -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chcon" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 297 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000463-GPOS-00207,SRG-OS-000465-GPOS-00209,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250 | CCE-83750-0 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the semanage command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "semanage" command with the following command: $ sudo auditctl -l | grep semanage -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "semanage" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 298 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000463-GPOS-00207,SRG-OS-000465-GPOS-00209,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250 | CCE-83736-9 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the setfiles command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "setfiles" command with the following command: $ sudo auditctl -l | grep setfiles -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "setfiles" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 299 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000463-GPOS-00207,SRG-OS-000465-GPOS-00209,SRG-APP-000495-CTR-001235,SRG-APP-000496-CTR-001240,SRG-APP-000497-CTR-001245,SRG-APP-000498-CTR-001250 | CCE-83751-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the setsebool command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "setsebool" command with the following command: $ sudo auditctl -l | grep setsebool -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate an audit event for any successful/unsuccessful use of the "setsebool " command by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 300 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-OS-000467-GPOS-00211,SRG-OS-000468-GPOS-00212,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83754-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the rename,unlink,rmdir,renameat, and unlinkat system calls. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit successful/unsuccessful attempts to use the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls with the following command: $ sudo auditctl -l | grep 'rename\|unlink\|rmdir' -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete If the command does not return an audit rule for "rename", "unlink", "rmdir", "renameat", and "unlinkat" or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate an audit event for any successful/unsuccessful use of the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 301 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-OS-000467-GPOS-00211,SRG-OS-000468-GPOS-00212,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83756-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the renameat system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the renameat system call, run the following command: $ sudo grep "renameat" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "renameat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S renameat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S renameat -F auid>=1000 -F auid!=unset -k delete It's allowed to group this system call within the same line as "rename", "unlink", "rmdir", "renameat", and "unlinkat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 302 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-OS-000467-GPOS-00211,SRG-OS-000468-GPOS-00212,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83758-3 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the rmdir system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the rmdir system call, run the following command: $ sudo grep "rmdir" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "rmdir" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S rmdir -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rmdir -F auid>=1000 -F auid!=unset -k delete It's allowed to group this system call within the same line as "rename", "unlink", "rmdir", "renameat", and "unlinkat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 303 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-OS-000467-GPOS-00211,SRG-OS-000468-GPOS-00212,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83757-5 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the unlink system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the unlink system call, run the following command: $ sudo grep "unlink" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "unlink" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S unlink -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlink -F auid>=1000 -F auid!=unset -k delete It's allowed to group this system call within the same line as "rename", "unlink", "rmdir", "renameat", and "unlinkat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 304 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-OS-000467-GPOS-00211,SRG-OS-000468-GPOS-00212,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83755-9 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the unlinkat system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the unlinkat system call, run the following command: $ sudo grep "unlinkat" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "unlinkat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S unlinkat -F auid>=1000 -F auid!=unset -k delete It's allowed to group this system call within the same line as "rename", "unlink", "rmdir", "renameat", and "unlinkat". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 305 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83786-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit successful/unsuccessful attempts to use the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls with the following command: $ sudo auditctl -l | grep'open\|truncate\|creat' -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access If the output does not produce rules containing "-F exit=-EPERM", this is a finding. If the output does not produce rules containing "-F exit=-EACCES", this is a finding. If the command does not return an audit rule for "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate an audit event for any successful/unsuccessful use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 306 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83800-3 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the ftruncate system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the ftruncate system call, run the following command: $ sudo grep "ftruncate" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "ftruncate" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access It's allowed to group this system call within the same line as "creat", "ftruncate", "truncate", "open", "openat" and "open_by_handle_at". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 307 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83801-1 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the open system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the open system call, run the following command: $ sudo grep "open" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "open" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access It's allowed to group this system call within the same line as "creat", "ftruncate", "truncate", "open", "openat" and "open_by_handle_at". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 308 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83796-3 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the open_by_handle_at system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the open_by_handle_at system call, run the following command: $ sudo grep "open_by_handle_at" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "open_by_handle_at" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access It's allowed to group this system call within the same line as "creat", "ftruncate", "truncate", "open", "openat" and "open_by_handle_at". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 309 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83794-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the openat system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the openat system call, run the following command: $ sudo grep "openat" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "openat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access It's allowed to group this system call within the same line as "creat", "ftruncate", "truncate", "open", "openat" and "open_by_handle_at". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 310 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000064-GPOS-00033,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-APP-000495-CTR-001235 | CCE-83792-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Successful/unsuccessful uses of the truncate system call in Red Hat Enterprise Linux 9 must generate an audit record. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
To determine if the system is configured to audit calls to the truncate system call, run the following command: $ sudo grep "truncate" /etc/audit/audit.* If the system is configured to audit this activity, it will return a line. If no line is returned, then this is a finding. |
Configure the audit system to generate an audit event for any successful/unsuccessful use of the "truncate" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access It's allowed to group this system call within the same line as "creat", "ftruncate", "truncate", "open", "openat" and "open_by_handle_at". The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 311 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000468-GPOS-00212,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-83765-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chage command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chage" command with the following command: $ sudo auditctl -l | grep chage -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chage" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 312 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83763-3 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the chsh command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "chsh" command with the following command: $ sudo auditctl -l | grep chsh -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "chsh" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 313 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83761-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the crontab command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "crontab" command with the following command: $ sudo auditctl -l | grep crontab -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-crontab If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "crontab" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-crontab The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 314 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83773-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the gpasswd command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "gpasswd" command with the following command: $ sudo auditctl -l | grep gpasswd -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-gpasswd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "gpasswd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-gpasswd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 315 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83766-6 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the newgrp command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "newgrp" command with the following command: $ sudo auditctl -l | grep newgrp -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "newgrp" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 316 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83767-4 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the pam_timestamp_check command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "pam_timestamp_check" command with the following command: $ sudo auditctl -l | grep timestamp -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam_timestamp_check If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "pam_timestamp_check" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam_timestamp_check The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 317 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83781-5 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the passwd command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify Red Hat Enterprise Linux 9 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow" with the following command: $ sudo auditctl -l | egrep '(/usr/bin/passwd)' -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "passwd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 318 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83769-0 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the postdrop command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "postdrop" command with the following command: $ sudo auditctl -l | grep postdrop -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "postdrop" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 319 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83770-8 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the postqueue command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "postqueue" command with the following command: $ sudo auditctl -l | grep postqueue -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "postqueue" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 320 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-90388-0 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the ssh-agent command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "ssh-agent" command with the following command: $ sudo auditctl -l | grep ssh-agent -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "ssh-agent" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 321 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83776-5 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the ssh-keysign command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "ssh-keysign" command with the following command: $ sudo auditctl -l | grep ssh-keysign -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "ssh-keysign" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 322 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085,SRG-APP-000495-CTR-001235 | CCE-83768-2 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the unix_chkpwd command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "unix_chkpwd" command with the following command: $ sudo auditctl -l | grep unix_chkpwd -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "unix_chkpwd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 323 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000064-GPOS-00033,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-89481-6 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the unix_update command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "unix_update" command with the following command: $ sudo auditctl -l | grep unix_update -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "unix_update" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 324 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83760-9 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the userhelper command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "userhelper" command with the following command: $ sudo auditctl -l | grep userhelper -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "userhelper" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 325 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-OS-000466-GPOS-00210,SRG-APP-000495-CTR-001235,SRG-APP-000499-CTR-001255 | CCE-87212-7 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the usermod command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "usermod" command with the following command: $ sudo auditctl -l | grep usermod -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "usermod " command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 326 | CCI-000130,CCI-000135,CCI-000169,CCI-000172,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000495-CTR-001235 | CCE-83735-1 | The operating system must provide audit record generation capability for DoD-defined auditable events for all operating system components. | Red Hat Enterprise Linux 9 must audit all uses of the mount command. | Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system is capable of generating audit records. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system provides audit record generation capability for DoD-defined auditable events for all operating system components. DoD has defined the list of events for which the operating system will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful logon attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logons from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. If it does not, this is a finding. |
Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "mount" command with the following command: $ sudo auditctl -l | grep /usr/bin/mount -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "mount" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": --a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 327 | CCI-000163,CCI-000164,CCI-000162 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-APP-000119-CTR-000245,SRG-APP-000120-CTR-000250 | CCE-83716-1 | The operating system must protect audit information from unauthorized modification. | Red Hat Enterprise Linux 9 audit system must protect auditing rules from unauthorized change. | If audit information were to become compromised, then forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve. To ensure the veracity of audit information, the operating system must protect audit information from unauthorized modification. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit information system activity. |
Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit Red Hat Enterprise Linux 9 system activity. In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. A system reboot would be noticeable, and a system administrator could then investigate the unauthorized changes. |
Applicable - Configurable | Verify the operating system protects audit information from unauthorized modification. If it does not, this is a finding. | Verify the audit system prevents unauthorized changes with the following command: $ sudo grep "^\s*[^#]" /etc/audit/audit.rules | tail -1 -e 2 If the audit system is not set to be immutable by adding the "-e 2" option to the end of "/etc/audit/audit.rules", this is a finding. |
Configure the audit system to set the audit rules to be immutable by adding the following line to end of "/etc/audit/rules.d/audit.rules" -e 2 The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 328 | CCI-000162,CCI-000163,CCI-000164 | SRG-OS-000462-GPOS-00206,SRG-OS-000475-GPOS-00220,SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029,SRG-APP-000121-CTR-000255,SRG-APP-000495-CTR-001235 | CCE-83673-4 | The operating system must protect audit information from unauthorized modification. | Red Hat Enterprise Linux 9 audit system must protect logon UIDs from unauthorized change. | If audit information were to become compromised, then forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve. To ensure the veracity of audit information, the operating system must protect audit information from unauthorized modification. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit information system activity. |
If modification of login UIDs is not prevented, they can be changed by unprivileged users and make auditing complicated or impossible. | Applicable - Configurable | Verify the operating system protects audit information from unauthorized modification. If it does not, this is a finding. | Verify the audit system prevents unauthorized changes to logon UIDs with the following command: $ sudo grep -i immutable /etc/audit/audit.rules --loginuid-immutable If the "--loginuid-immutable" option is not returned in the "/etc/audit/audit.rules", or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 auditing to prevent modification of login UIDs once they are set by adding the following line to /etc/audit/rules.d/audit.rules: --loginuid-immutable The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 329 | CCI-002605 | SRG-OS-000439-GPOS-00195 | The operating system must install security-relevant software updates within the time period directed by an authoritative source (e.g., IAVM, CTOs, DTMs, and STIGs). | The operating system must install security-relevant software updates within the time period directed by an authoritative source (e.g., IAVM, CTOs, DTMs, and STIGs). | Security flaws with operating systems are discovered daily. Vendors are constantly updating and patching their products to address newly discovered security vulnerabilities. Organizations (including any contractor to the organization) are required to promptly install security-relevant software updates (e.g., patches, service packs, and hot fixes). Flaws discovered during security assessments, continuous monitoring, incident response activities, or information system error handling must also be addressed expeditiously. | pending | Review the operating system documentation and configuration to determine if the operating system checks with a patch management system to install security-relevant software updates within a timeframe directed by an authoritative source. If the operating system does not install security-relevant patches within the time period directed by the authoritative source, this is a finding. |
CAT II | |||||||||
| 330 | CCI-002702,CCI-001744,CCI-002699 | SRG-OS-000363-GPOS-00150,SRG-OS-000446-GPOS-00200,SRG-OS-000447-GPOS-00201 | CCE-83437-4 | The operating system must perform verification of the correct operation of security functions: upon system start-up and/or restart; upon command by a user with privileged access; and/or every 30 days. | Red Hat Enterprise Linux 9 must routinely check the baseline configuration for unauthorized changes and notify the system administrator when anomalies in the operation of any security functions are discovered. | Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. Notifications provided by information systems include, for example, electronic alerts to system administrators, messages to local computer consoles, and/or hardware indications, such as lights. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. |
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. Notifications provided by information systems include messages to local computer consoles, and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. |
Applicable - Configurable | Verify the operating system performs verification of the correct operation of security functions: upon system start-up and/or restart; upon command by a user with privileged access; and/or every 30 days. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 routinely executes a file integrity scan for changes to the system baseline. The command used in the example will use a daily occurrence. Check the cron directories for scripts controlling the execution and notification of results of the file integrity application. For example, if AIDE is installed on the system, use the following commands: $ ls -al /etc/cron.* | grep aide -rwxr-xr-x 1 root root 29 Nov 22 2015 aide $ grep aide /etc/crontab /var/spool/cron/root /etc/crontab: 30 04 * * * root usr/sbin/aide /var/spool/cron/root: 30 04 * * * root usr/sbin/aide $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily aide integrity check run" root@sysname.mil If the file integrity application does not exist, or a script file controlling the execution of the file integrity application does not exist, or the file integrity application does not notify designated personnel of changes, this is a finding. |
Configure the file integrity tool to run automatically on the system at least weekly and to notify designated personnel if baseline configurations are changed in an unauthorized manner. The AIDE tool can be configured to email designated personnel with the use of the cron system. The following example output is generic. It will set cron to run AIDE daily and to send email at the completion of the analysis. $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily aide integrity check run" root@sysname.mil |
CAT II | |||||
| 331 | CCI-002476,CCI-001199,CCI-002475 | SRG-OS-000405-GPOS-00184,SRG-OS-000185-GPOS-00079,SRG-OS-000404-GPOS-00183 | CCE-90849-1 | The operating system must implement cryptographic mechanisms to prevent unauthorized disclosure of all information at rest on all operating system components. | Red Hat Enterprise Linux 9 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. | Operating systems handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). |
Red Hat Enterprise Linux 9 systems handling data requiring "data at rest" protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). |
Applicable - Configurable | Verify the operating system implements cryptographic mechanisms to prevent unauthorized disclosure of all information at rest on all operating system components. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents unauthorized disclosure or modification of all information requiring at-rest protection by using disk encryption. Note: If there is a documented and approved reason for not having data-at-rest encryption, this requirement is Not Applicable. Verify all system partitions are encrypted with the following command: $ blkid /dev/map per/rhel-root: UUID="67b7d7fe-de60-6fd0-befb-e6748cf97743" TYPE="crypto_LUKS" Every persistent disk partition present must be of type "crypto_LUKS". If any partitions other than the boot partition or pseudo file systems (such as /proc or /sys) or temporary file systems (that are tmpfs) are not type "crypto_LUKS", ask the administrator to indicate how the partitions are encrypted. If there is no evidence that these partitions are encrypted, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent unauthorized modification of all information at rest by using disk encryption. Encrypting a partition in an already installed system is more difficult, because existing partitions will need to be resized and changed. To encrypt an entire partition, dedicate a partition for encryption in the partition layout. |
CAT I | |||||
| 332 | CCI-002754 | SRG-OS-000432-GPOS-00191 | The operating system must behave in a predictable and documented manner that reflects organizational and system objectives when invalid inputs are received. | Red Hat Enterprise Linux 9 must behave in a predictable and documented manner that reflects organizational and system objectives when invalid inputs are received. | A common vulnerability of operating system is unpredictable behavior when invalid inputs are received. This requirement guards against adverse or unintended system behavior caused by invalid inputs, where information system responses to the invalid input may be disruptive or cause the system to fail into an unsafe state. The behavior will be derived from the organizational and system requirements and includes, but is not limited to, notification of the appropriate personnel, creating an audit record, and rejecting invalid input. |
A common vulnerability of operating system is unpredictable behavior when invalid inputs are received. This requirement guards against adverse or unintended system behavior caused by invalid inputs, where information system responses to the invalid input may be disruptive or cause the system to fail into an unsafe state. The behavior will be derived from the organizational and system requirements and includes, but is not limited to, notification of the appropriate personnel, creating an audit record, and rejecting invalid input. |
Applicable - Inherently Met | Verify the operating system behaves in a predictable and documented manner that reflects organizational and system objectives when invalid inputs are received. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. | Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. | CAT II | The Red Hat Enterprise Linux 9 operating system is tested by the vendor within the standards of the software industry for inconsistent actions based on known inputs. | Manpages for system calls contain description of errors returned when invalid input are received. Network protocols have RFCs associated which describe the expected behavior when those protocols receive invalid input. The Red Hat Enterprise Linux 9 Linux kernel implements those protocols by following the RFC and properly dealing with invalid inputs. | ||||
| 333 | CCI-000765,CCI-000766 | SRG-OS-000105-GPOS-00052,SRG-OS-000106-GPOS-00053,SRG-OS-000107-GPOS-00054,SRG-OS-000108-GPOS-00055 | CCE-86138-5 | The operating system must use multifactor authentication for network access to non-privileged accounts. | Red Hat Enterprise Linux 9 SSHD must accept public key authentication. | To assure accountability and prevent unauthenticated access, non-privileged users must utilize multifactor authentication to prevent potential misuse and compromise of the system. Multifactor authentication uses two or more factors to achieve authentication. Factors include: 1) Something you know (e.g., password/PIN); 2) Something you have (e.g., cryptographic identification device, token); and 3) Something you are (e.g., biometric). A non-privileged account is any information system account with authorizations of a non-privileged user. Network access is any access to an application by a user (or process acting on behalf of a user) where said access is obtained through a network connection. The DoD CAC with DoD-approved PKI is an example of multifactor authentication. |
Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. A DOD common access card (CAC) with DOD-approved PKI is an example of multifactor authentication. | Applicable - Configurable | Verify the operating system uses multifactor authentication for network access to non-privileged accounts. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 SSH daemon accepts public key encryption with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*pubkeyauthentication' PubkeyAuthentication yes If "PubkeyAuthentication" is set to no, the line is commented out, or the line is missing, this is a finding. |
To configure the system add or modify the following line in "/etc/ssh/sshd_config". PubkeyAuthentication yes Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 334 | CCI-001941,CCI-004045,CCI-000765,CCI-000766,CCI-000764 | SRG-OS-000104-GPOS-00051,SRG-OS-000106-GPOS-00053,SRG-OS-000107-GPOS-00054,SRG-OS-000109-GPOS-00056,SRG-OS-000108-GPOS-00055,SRG-OS-000108-GPOS-00057,SRG-OS-000108-GPOS-00058 | CCE-89122-6 | The operating system must use multifactor authentication for network access to non-privileged accounts. | Red Hat Enterprise Linux 9 must use the cac smartcard driver. | To assure accountability and prevent unauthenticated access, non-privileged users must utilize multifactor authentication to prevent potential misuse and compromise of the system. Multifactor authentication uses two or more factors to achieve authentication. Factors include: 1) Something you know (e.g., password/PIN); 2) Something you have (e.g., cryptographic identification device, token); and 3) Something you are (e.g., biometric). A non-privileged account is any information system account with authorizations of a non-privileged user. Network access is any access to an application by a user (or process acting on behalf of a user) where said access is obtained through a network connection. The DoD CAC with DoD-approved PKI is an example of multifactor authentication. |
Smart card login provides two-factor authentication stronger than that provided by a username and password combination. Smart cards leverage public key infrastructure in order to provide and verify credentials. Configuring the smart card driver in use by your organization helps to prevent users from using unauthorized smart cards. |
Applicable - Configurable | Verify the operating system uses multifactor authentication for network access to non-privileged accounts. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 loads the cac driver with the following command: $ grep card_drivers /etc/opensc.conf card_drivers = cac; If "cac" is not listed as a card driver, or there is no line returned for "card_drivers", this is a finding. |
Configure Red Hat Enterprise Linux 9 to load the cac driver. Add, or modify the following line in the "/etc/opensc.conf" file: card_drivers = cac; |
CAT II | |||||
| 335 | CCI-002702,CCI-001744,CCI-002699 | SRG-OS-000363-GPOS-00150,SRG-OS-000446-GPOS-00200,SRG-OS-000447-GPOS-00201 | CCE-90844-2 | The operating system must shut down the information system, restart the information system, and/or notify the system administrator when anomalies in the operation of any security functions are discovered. | Red Hat Enterprise Linux 9 Must Shut Down The Information System, Restart The Information System, And/Or Notify The System Administrator When Anomalies In The Operation Of Any Security Functions Are Discovered. | If anomalies are not acted upon, security functions may fail to secure the system. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. Notifications provided by information systems include messages to local computer consoles, and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. |
Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. |
Applicable - Configurable | Verify the operating system shuts down the information system, restarts the information system, and/or notifies the system administrator when anomalies in the operation of any security functions are discovered. If it does not, this is a finding. | To determine that periodic AIDE execution has been scheduled, run the following command: $ grep aide /etc/crontab The output should return something similar to the following: 05 4 * * * root /usr/sbin/aide --check | /bin/mail -s "$(hostname) - AIDE Integrity Check" root@localhost The email address that the notifications are sent to can be changed by overriding root@localhost . If AIDE has not been configured or has not been configured to notify personnel of scan details, then this is a finding. |
Configure the file integrity tool to run automatically on the system at least weekly and to notify designated personnel if baseline configurations are changed in an unauthorized manner. The AIDE tool can be configured to email designated personnel with the use of the cron system. The following example output is generic. It will set cron to run AIDE daily and to send email at the completion of the $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily aide integrity check run" root@sysname.mil |
CAT II | |||||
| 336 | CCI-004066 | SRG-OS-000072-GPOS-00040,SRG-OS-000071-GPOS-00039,SRG-OS-000070-GPOS-00038,SRG-OS-000266-GPOS-00101,SRG-OS-000078-GPOS-00046,SRG-OS-000480-GPOS-00225,SRG-OS-000069-GPOS-00037 | CCE-86356-3 | The operating system must enforce a minimum 15-character password length. | Red Hat Enterprise Linux 9 must enforce password complexity rules for the root account. | The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Applicable - Configurable | Verify the operating system enforces a minimum 15-character password length. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces password complexity rules for the root account. Check if root user is required to use complex passwords with the following command: $ grep enforce_for_root /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:enforce_for_root If "enforce_for_root" is commented or missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce password complexity on the root account. Add or update the following line in /etc/security/pwquality.conf: enforce_for_root |
CAT II | |||||
| 337 | CCI-004066 | SRG-OS-000078-GPOS-00046 | CCE-83579-3 | The operating system must enforce a minimum 15-character password length. | Red Hat Enterprise Linux 9 passwords must be created with a minimum of 15 characters. | The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password. |
The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password. Red Hat Enterprise Linux 9 utilizes "pwquality" as a mechanism to enforce password complexity. Configurations are set in the "etc/security/pwquality.conf" file. The "minlen", sometimes noted as minimum length, acts as a "score" of complexity based on the credit components of the "pwquality" module. By setting the credit components to a negative value, not only will those components be required, they will not count towards the total "score" of "minlen". This will enable "minlen" to require a 15-character minimum. The DoD minimum password requirement is 15 characters. |
Applicable - Configurable | Verify the operating system enforces a minimum 15-character password length. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces a minimum 15-character password length with the following command: $ grep minlen /etc/security/pwquality.conf minlen = 15 If the command does not return a "minlen" value of "15" or greater, does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce a minimum 15-character password length. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): minlen = 15 |
CAT II | |||||
| 338 | CCI-000366 | SRG-OS-000480-GPOS-00229 | CCE-90816-0 | The operating system must not allow an unattended or automatic logon to the system. | Red Hat Enterprise Linux 9 must not allow a noncertificate trusted host SSH logon to the system. | Failure to restrict system access to authenticated users negatively impacts operating system security. | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. | Applicable - Configurable | If the operating system provides a public access service, such as a kiosk, this is not applicable. Verify the operating system does not allow an unattended or automatic logon to the system. If it does, this is a finding. Automatic logon as an authorized user allows access to any user with physical access to the operating system. | Verify the operating system does not allow a noncertificate trusted host SSH logon to the system with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*hostbasedauthentication' HostbasedAuthentication no If the "HostbasedAuthentication" keyword is not set to "no", is missing, or is commented out, this is a finding. If the required value is not set, this is a finding. |
To configure Red Hat Enterprise Linux 9 to not allow a noncertificate trusted host SSH logon to the system add or modify the following line in "/etc/ssh/sshd_config". HostbasedAuthentication no Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT I | |||||
| 339 | CCI-000366 | SRG-OS-000480-GPOS-00229 | CCE-90803-8 | The operating system must not allow an unattended or automatic logon to the system. | Red Hat Enterprise Linux 9 must not allow users to override SSH environment variables. | Failure to restrict system access to authenticated users negatively impacts operating system security. | SSH environment options potentially allow users to bypass access restriction in some configurations. | Applicable - Configurable | If the operating system provides a public access service, such as a kiosk, this is not applicable. Verify the operating system does not allow an unattended or automatic logon to the system. If it does, this is a finding. Automatic logon as an authorized user allows access to any user with physical access to the operating system. | Verify that unattended or automatic logon via SSH is disabled with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*permituserenvironment' PermitUserEnvironment no If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding. If the required value is not set, this is a finding. |
Configure the Red Hat Enterprise Linux 9 SSH daemon to not allow unattended or automatic logon to the system. Add or edit the following line in the "/etc/ssh/sshd_config" file: PermitUserEnvironment no Restart the SSH daemon for the setting to take effect: $ sudo systemctl restart sshd.service |
CAT I | |||||
| 340 | CCI-000366 | SRG-OS-000480-GPOS-00229 | CCE-89663-9 | The operating system must not allow an unattended or automatic logon to the system. | Red Hat Enterprise Linux 9 must not allow unattended or automatic logon via the graphical user interface. | Failure to restrict system access to authenticated users negatively impacts operating system security. | Failure to restrict system access to authenticated users negatively impacts operating system security. | Applicable - Configurable | If the operating system provides a public access service, such as a kiosk, this is not applicable. Verify the operating system does not allow an unattended or automatic logon to the system. If it does, this is a finding. Automatic logon as an authorized user allows access to any user with physical access to the operating system. | Verify Red Hat Enterprise Linux 9 does not allow an unattended or automatic logon to the system via a graphical user interface. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Check for the value of the "AutomaticLoginEnable" in the "/etc/gdm/custom.conf" file with the following command: $ grep -i automaticlogin /etc/gdm/custom.conf [daemon] AutomaticLoginEnable=false If the value of "AutomaticLoginEnable" is not set to "false", this is a finding. |
Configure the GNOME desktop display manager to disable automatic login. Set AutomaticLoginEnable to false in the [daemon] section in /etc/gdm/custom.conf. For example: [daemon] AutomaticLoginEnable=false |
CAT I | |||||
| 341 | CCI-001133,CCI-002361,CCI-002891 | SRG-OS-000126-GPOS-00066,SRG-OS-000163-GPOS-00072,SRG-OS-000279-GPOS-00109,SRG-OS-000395-GPOS-00175 | CCE-90811-1 | The operating system must automatically terminate a user session after inactivity time-outs have expired or at shutdown. | The Red Hat Enterprise Linux 9 SSH daemon must be configured with a timeout interval. | Automatic session termination addresses the termination of user-initiated logical sessions in contrast to the termination of network connections that are associated with communications sessions (i.e., network disconnect). A logical session (for local, network, and remote access) is initiated whenever a user (or process acting on behalf of a user) accesses an organizational information system. Such user sessions can be terminated (and thus terminate user access) without terminating network sessions. Session termination terminates all processes associated with a user's logical session except those processes that are specifically created by the user (i.e., session owner) to continue after the session is terminated. Conditions or trigger events requiring automatic session termination can include, for example, organization-defined periods of user inactivity, targeted responses to certain types of incidents, and time-of-day restrictions on information system use. This capability is typically reserved for specific operating system functionality where the system owner, data owner, or organization requires additional assurance. |
Terminating an idle SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. Red Hat Enterprise Linux 9 utilizes /etc/ssh/sshd_config for configurations of OpenSSH. Within the sshd_config the product of the values of "ClientAliveInterval" and "ClientAliveCountMax" are used to establish the inactivity threshold. The "ClientAliveInterval" is a timeout interval in seconds after which if no data has been received from the client, sshd will send a message through the encrypted channel to request a response from the client. The "ClientAliveCountMax" is the number of client alive messages that may be sent without sshd receiving any messages back from the client. If this threshold is met, sshd will disconnect the client. For more information on these settings and others, refer to the sshd_config man pages. |
Applicable - Configurable | Verify the operating system automatically terminates a user session after inactivity time-outs have expired or at shutdown. If it does not, this is a finding. | Verify that the "ClientAliveInterval" variable is set to a value of "600" or less by performing the following command: $ sudo grep -i interval /etc/ssh/sshd_config ClientAliveInterval 600 If "ClientAliveInterval" does not exist, does not have a value of "600" or less in "/etc/ssh/sshd_config", or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to automatically terminate all network connections associated with SSH traffic at the end of a session or after 10 minutes of inactivity. Modify or append the following lines in the "/etc/ssh/sshd_config" file: ClientAliveInterval 600 In order for the changes to take effect, the SSH daemon must be restarted. $ sudo systemctl restart sshd.service |
CAT II | |||||
| 342 | CCI-000057,CCI-001133 | SRG-OS-000163-GPOS-00072,SRG-OS-000029-GPOS-00010 | CCE-83633-8 | The operating system must automatically terminate a user session after inactivity time-outs have expired or at shutdown. | Red Hat Enterprise Linux 9 must automatically exit interactive command shell user sessions after 15 minutes of inactivity. | Automatic session termination addresses the termination of user-initiated logical sessions in contrast to the termination of network connections that are associated with communications sessions (i.e., network disconnect). A logical session (for local, network, and remote access) is initiated whenever a user (or process acting on behalf of a user) accesses an organizational information system. Such user sessions can be terminated (and thus terminate user access) without terminating network sessions. Session termination terminates all processes associated with a user's logical session except those processes that are specifically created by the user (i.e., session owner) to continue after the session is terminated. Conditions or trigger events requiring automatic session termination can include, for example, organization-defined periods of user inactivity, targeted responses to certain types of incidents, and time-of-day restrictions on information system use. This capability is typically reserved for specific operating system functionality where the system owner, data owner, or organization requires additional assurance. |
Terminating an idle interactive command shell user session within a short time period reduces the window of opportunity for unauthorized personnel to take control of it when left unattended in a virtual terminal or physical console. | Applicable - Configurable | Verify the operating system automatically terminates a user session after inactivity time-outs have expired or at shutdown. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to exit interactive command shell user sessions after 15 minutes of inactivity or less with the following command: $ sudo grep -i tmout /etc/profile /etc/profile.d/*.sh /etc/profile.d/tmout.sh:declare -xr TMOUT=900 If "TMOUT" is not set to "900" or less in a script located in the "/etc/'profile.d/ directory, is missing or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to exit interactive command shell user sessions after 15 minutes of inactivity. Add or edit the following line in "/etc/profile.d/tmout.sh": #!/bin/bash declare -xr TMOUT=900 |
CAT II | |||||
| 343 | CCI-001967 | SRG-OS-000379-GPOS-00164 | The operating system must authenticate all endpoint devices before establishing a local, remote, and/or network connection using bidirectional authentication that is cryptographically based. | Red Hat Enterprise Linux 9 must authenticate all endpoint devices before establishing a local, remote, and/or network connection using bidirectional authentication that is cryptographically based. | Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Bidirectional authentication provides stronger safeguards to validate the identity of other devices for connections that are of greater risk. Bidirectional authentication solutions include, but are not limited to, IEEE 802.1x and Extensible Authentication Protocol [EAP], RADIUS server with EAP-Transport Layer Security [TLS] authentication, Kerberos, and SSL mutual authentication. A local connection is any connection with a device communicating without the use of a network. A network connection is any connection with a device that communicates through a network (e.g., local area network, wide area network, or the Internet). A remote connection is any connection with a device communicating through an external network (e.g., the Internet). Because of the challenges of applying this requirement on a large scale, organizations are encouraged to only apply this requirement to those limited number (and type) of devices that truly need to support this capability. |
Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Bidirectional authentication provides stronger safeguards to validate the identity of other devices for connections that are of greater risk. Bidirectional authentication solutions include, but are not limited to, IEEE 802.1x and Extensible Authentication Protocol [EAP], RADIUS server with EAP-Transport Layer Security [TLS] authentication, Kerberos, and SSL mutual authentication. A local connection is any connection with a device communicating without the use of a network. A network connection is any connection with a device that communicates through a network (e.g., local area network, wide area network, or the Internet). A remote connection is any connection with a device communicating through an external network (e.g., the internet). Because of the challenges of applying this requirement on a large scale, organizations are encouraged to only apply this requirement to those limited number (and type) of devices that truly need to support this capability. |
Not Applicable | Verify the operating system authenticates all endpoint devices before establishing a local, remote, and/or network connection using bidirectional authentication that is cryptographically based. If it does not, this is a finding. | This requirement is NA for Red Hat Enterprise Linux 9. | The requirement is NA. No fix is required. | CAT II | This requirement is not valid for general-purpose operating systems and currently is impossible to implement in any operating system not designed for extreme multilevel protections. | |||||
| 344 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-89858-5 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library directories must be group-owned by root or a system account. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library directories are group-owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -group root -type d -exec stat -c "%n %G" '{}' \; If any system-wide shared library directory is returned and is not group-owned by a required system account, this is a finding. |
Configure the system-wide shared library directories (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not group-owned by "root". $ sudo chgrp root [DIRECTORY] |
CAT II | |||||
| 345 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-89022-8 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library directories must be owned by root. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library directories are owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -user root -type d -exec stat -c "%n %U" '{}' \; If any system-wide shared library directory is not owned by root, this is a finding. |
Configure the system-wide shared library directories within (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not owned by "root". $ sudo chown root [DIRECTORY] |
CAT II | |||||
| 346 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-89442-8 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 system commands must be group-owned by root or a system account. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system commands contained in the following directories are group-owned by "root", or a required system account, with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin ! -group root -exec ls -l {} \; If any system commands are returned and is not group-owned by a required system account, this is a finding. |
Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not group-owned by "root" or a required system account. $ sudo chgrp root [FILE] |
CAT II | |||||
| 347 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-83908-4 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 system commands must be owned by root. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system commands contained in the following directories are owned by "root" with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/libexec /usr/local/bin /usr/local/sbin ! -user root -exec ls -l {} \; If any system commands are found to not be owned by root, this is a finding. |
Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not owned by "root". $ sudo chown root [FILE] |
CAT II | |||||
| 348 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-83907-6 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library files must be owned by root. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library files are owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -user root -exec ls -l {} \; If any system-wide shared library file is not owned by root, this is a finding. |
Configure the system-wide shared library files (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not owned by "root". $ sudo chown root [FILE] |
CAT II | |||||
| 349 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-83911-8 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 system commands must have mode 755 or less permissive. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system commands contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/libexec /usr/local/bin /usr/local/sbin -perm /022 -exec ls -l {} \; If any system commands are found to be group-writable or world-writable, this is a finding. |
Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command with a mode more permissive than "755". $ sudo chmod 755 [FILE] |
CAT II | |||||
| 350 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-88693-7 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library directories must have mode 755 or less permissive. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library directories have mode "755" or less permissive with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type d -exec ls -l {} \; If any system-wide shared library file is found to be group-writable or world-writable, this is a finding. |
Configure the system-wide shared library directories (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory with a mode more permissive than 755. $ sudo chmod 755 [DIRECTORY] |
CAT II | |||||
| 351 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-83909-2 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library files must have mode 755 or less permissive. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library files contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type f -exec ls -l {} \; If any system-wide shared library file is found to be group-writable or world-writable, this is a finding. |
Configure the library files to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file with a mode more permissive than 755. $ sudo chmod 755 [FILE] |
CAT II | |||||
| 352 | CCI-001499 | SRG-OS-000259-GPOS-00100 | CCE-87108-7 | The operating system must limit privileges to change software resident within software libraries. | Red Hat Enterprise Linux 9 library files must be group-owned by root or a system account. | If the operating system were to allow any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to operating systems with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs which execute with escalated privileges. Only qualified and authorized individuals shall be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
If Red Hat Enterprise Linux 9 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to Red Hat Enterprise Linux 9 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. |
Applicable - Configurable | Verify the operating system limits privileges to change software resident within software libraries. If it does not, this is a finding. | Verify the system-wide shared library files are group-owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -group root -exec ls -l {} \; If any system-wide shared library file is returned and is not group-owned by a required system account, this is a finding. |
Configure the system-wide shared library files (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not group-owned by "root". $ sudo chgrp root [FILE] |
CAT II | |||||
| 353 | CCI-000382,CCI-002314 | SRG-OS-000096-GPOS-00050,SRG-OS-000297-GPOS-00115 | CCE-86041-1 | The operating system must control remote access methods. | Red Hat Enterprise Linux 9 must control remote access methods. | Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Operating system functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). |
To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business. |
Applicable - Configurable | Verify the operating system controls remote access methods. If it does not, this is a finding. | Inspect the list of enabled firewall ports and verify they are configured correctly by running the following command: $ sudo firewall-cmd --list-all Ask the system administrator for the site or program Ports, Protocols, and Services Management Component Local Service Assessment (PPSM CLSA). Verify the services allowed by the firewall match the PPSM CLSA. If there are additional ports, protocols, or services that are not in the PPSM CLSA, or there are ports, protocols, or services that are prohibited by the PPSM Category Assurance List (CAL), or there are no firewall rules configured, this is a finding. |
Configure Red Hat Enterprise Linux 9 to allow approved settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL. To open a port for a service, configure firewalld using the following command: $ sudo firewall-cmd --permanent --add-port=port_number/tcp or $ sudo firewall-cmd --permanent --add-service=service_name |
CAT II | |||||
| 354 | CCI-000877 | SRG-OS-000125-GPOS-00065 | CCE-86722-6 | The operating system must employ strong authenticators in the establishment of nonlocal maintenance and diagnostic sessions. | Red Hat Enterprise Linux 9 must enable the Pluggable Authentication Module (PAM) interface for SSHD. | If maintenance tools are used by unauthorized personnel, they may accidentally or intentionally damage or compromise the system. The act of managing systems and applications includes the ability to access sensitive application information, such as system configuration details, diagnostic information, user information, and potentially sensitive application data. Some maintenance and test tools are either standalone devices with their own operating systems or are applications bundled with an operating system. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. Typically, strong authentication requires authenticators that are resistant to replay attacks and employ multifactor authentication. Strong authenticators include, for example, PKI where certificates are stored on a token protected by a password, passphrase, or biometric. |
When UsePAM is set to "yes", PAM runs through account and session types properly. This is important when restricted access to services based off of IP, time, or other factors of the account is needed. Additionally, this ensures users can inherit certain environment variables on login or disallow access to the server. | Applicable - Configurable | Verify the operating system employs strong authenticators in the establishment of nonlocal maintenance and diagnostic sessions. If it does not, this is a finding. | Verify the Red Hat Enterprise Linux 9 SSHD is configured to allow for the UsePAM interface with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*usepam' UsePAM yes If the "UsePAM" keyword is set to "no", is missing, or is commented out, this is a finding. |
Configure the Red Hat Enterprise Linux 9 SSHD to use the UsePAM interface add or modify the following line in "/etc/ssh/sshd_config". UsePAM yes Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT I | |||||
| 355 | CCI-001190 | SRG-OS-000184-GPOS-00078 | The operating system must fail to a secure state if system initialization fails, shutdown fails, or aborts fail. | Red Hat Enterprise Linux 9 must fail to a secure state if system initialization fails, shutdown fails, or aborts fail. | Failure to a known safe state helps prevent systems from failing to a state that may cause loss of data or unauthorized access to system resources. Operating systems that fail suddenly and with no incorporated failure state planning may leave the system available but with a reduced security protection capability. Preserving operating system state information also facilitates system restart and return to the operational mode of the organization with less disruption to mission-essential processes. Abort refers to stopping a program or function before it has finished naturally. The term abort refers to both requested and unexpected terminations. |
Failure to a known safe state helps prevent systems from failing to a state that may cause loss of data or unauthorized access to system resources. Operating systems that fail suddenly and with no incorporated failure state planning may leave the system available but with a reduced security protection capability. Preserving operating system state information also facilitates system restart and return to the operational mode of the organization with less disruption to mission-essential processes. Abort refers to stopping a program or function before it has finished naturally. The term abort refers to both requested and unexpected terminations. |
Applicable - Inherently Met | Verify the operating system fails to a secure state if system initialization fails, shutdown fails, or aborts fail. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. | CAT II | Red Hat Enterprise Linux 9 is secure in the event of a failure. Authentication and authorizations are still necessary to access the system. | |||||
| 356 | CCI-002420,CCI-002421,CCI-002418,CCI-002422 | SRG-OS-000423-GPOS-00187,SRG-OS-000424-GPOS-00188,SRG-OS-000425-GPOS-00189,SRG-OS-000426-GPOS-00190 | CCE-90823-6 | The operating system must protect the confidentiality and integrity of transmitted information. | All Red Hat Enterprise Linux 9 networked systems must have SSH installed. | Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. |
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. |
Applicable - Configurable | Verify the operating system protects the confidentiality and integrity of transmitted information. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the openssh-server package installed with the following command: $ sudo dnf list --installed openssh-server Example output: openssh-server.x86_64 8.7p1-8.el9 If the "openssh-server" package is not installed, this is a finding. |
The openssh-server package can be installed with the following command: $ sudo dnf install openssh-server |
CAT I | |||||
| 357 | CCI-002420,CCI-002421,CCI-002418,CCI-002422 | SRG-OS-000423-GPOS-00187,SRG-OS-000424-GPOS-00188,SRG-OS-000425-GPOS-00189,SRG-OS-000426-GPOS-00190 | CCE-90822-8 | The operating system must protect the confidentiality and integrity of transmitted information. | All Red Hat Enterprise Linux 9 networked systems must have and implement SSH to protect the confidentiality and integrity of transmitted and received information, as well as information during preparation for transmission. | Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. |
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. |
Applicable - Configurable | Verify the operating system protects the confidentiality and integrity of transmitted information. If it does not, this is a finding. | Verify that "sshd" is active with the following command: $ systemctl is-active sshd active If the "sshd" service is not active, this is a finding. |
To enable the sshd service run the following command: $ systemctl enable --now sshd |
CAT I | |||||
| 358 | CCI-002418,CCI-002422 | SRG-OS-000423-GPOS-00187,SRG-OS-000426-GPOS-00190 | CCE-83451-5 | The operating system must protect the confidentiality and integrity of transmitted information. | Red Hat Enterprise Linux 9 must implement DOD-approved encryption in the bind package. | Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. |
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. Red Hat Enterprise Linux 9 incorporates system-wide crypto policies by default. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/ directory. |
Applicable - Configurable | Verify the operating system protects the confidentiality and integrity of transmitted information. If it does not, this is a finding. | Verify that BIND uses the system crypto policy with the following command: Note: If the "bind" package is not installed, this requirement is Not Applicable. $ sudo grep include /etc/named.conf include "/etc/crypto-policies/back-ends/bind.config";' If BIND is installed and the BIND config file doesn't contain the include "/etc/crypto-policies/back-ends/bind.config" directive, or the line is commented out, this is a finding. |
Configure BIND to use the system crypto policy. Add the following line to the "options" section in "/etc/named.conf": include "/etc/crypto-policies/back-ends/bind.config"; |
CAT I | |||||
| 359 | CCI-002696,CCI-001744 | SRG-OS-000445-GPOS-00199 | CCE-90843-4 | The operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. | Red Hat Enterprise Linux 9 must have the AIDE package installed. | Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. |
Without verification of the security functions, security functions may not operate correctly, and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. | Applicable - Configurable | Verify the operating system notifies designated personnel if baseline configurations are changed in an unauthorized manner. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the Advanced Intrusion Detection Environment (AIDE) package installed with the following command: $ sudo dnf list --installed aide Example output: aide.x86_64 0.16.100.el9 If AIDE is not installed, ask the system administrator (SA) how file integrity checks are performed on the system. If there is no application installed to perform integrity checks, this is a finding. If AIDE is installed, check if it has been initialized with the following command: $ sudo /usr/sbin/aide --check If the output is "Couldn't open file /var/lib/aide/aide.db.gz for reading", this is a finding. |
Install AIDE, initialize it, and perform a manual check. Install AIDE: $ sudo dnf install aide Initialize AIDE: $ sudo /usr/sbin/aide --init Example output: Start timestamp: 2023-06-05 10:09:04 -0600 (AIDE 0.16) AIDE initialized database at /var/lib/aide/aide.db.new.gz Number of entries: 86833 --------------------------------------------------- The attributes of the (uncompressed) database(s): --------------------------------------------------- /var/lib/aide/aide.db.new.gz MD5 : coZUtPHhoFoeD7+k54fUvQ== SHA1 : DVpOEMWJwo0uPgrKZAygIUgSxeM= SHA256 : EQiZH0XNEk001tcDmJa+5STFEjDb4MPE TGdBJ/uvZKc= SHA512 : 86KUqw++PZhoPK0SZvT3zuFq9yu9nnPP toei0nENVELJ1LPurjoMlRig6q69VR8l +44EwO9eYyy9nnbzQsfG1g== End timestamp: 2023-06-05 10:09:57 -0600 (run time: 0m 53s) The new database will need to be renamed to be read by AIDE: $ sudo mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz Perform a manual check: $ sudo /usr/sbin/aide --check Example output: 2023-06-05 10:16:08 -0600 (AIDE 0.16) AIDE found NO differences between database and filesystem. Looks okay!! ... |
CAT II | |||||
| 360 | CCI-001744 | SRG-OS-000363-GPOS-00150 | CCE-86608-7 | The operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. | Red Hat Enterprise Linux 9 must have the s-nail package installed. | Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. |
The "s-nail" package provides the mail command required to allow sending email notifications of unauthorized configuration changes to designated personnel. | Applicable - Configurable | Verify the operating system notifies designated personnel if baseline configurations are changed in an unauthorized manner. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to allow sending email notifications. Note: The "s-nail" package provides the "mail" command that is used to send email messages. Verify that the "s-nail" package is installed on the system: $ sudo dnf list --installed s-nail s-nail.x86_64 14.9.22-6.el9 If "s-nail" package is not installed, this is a finding. |
The s-nail package can be installed with the following command: $ sudo dnf install s-nail |
CAT II | |||||
| 361 | CCI-002696,CCI-001744 | SRG-OS-000445-GPOS-00199 | CCE-83438-2 | The operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. | Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. |
Applicable - Configurable | Verify the operating system notifies designated personnel if baseline configurations are changed in an unauthorized manner. If it does not, this is a finding. | CAT II | |||||||||
| 362 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-88939-4 | The operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. | Red Hat Enterprise Linux 9 must use a file integrity tool that is configured to use FIPS 140-3-approved cryptographic hashes for validating file contents and directories. | Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's IMO/ISSO and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. |
Red Hat Enterprise Linux 9 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. File integrity tools use cryptographic hashes for verifying file contents and directories have not been altered. These hashes must be FIPS 140-2/140-3-approved cryptographic hashes. |
Applicable - Configurable | Verify the operating system notifies designated personnel if baseline configurations are changed in an unauthorized manner. If it does not, this is a finding. | Verify that AIDE is configured to use FIPS 140-2/140-3 file hashing with the following command: $ grep sha512 /etc/aide.conf All=p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "sha512" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or another file integrity tool is not using FIPS 140-2/140-3-approved cryptographic hashes for validating file contents and directories, this is a finding. |
Configure the file integrity tool to use FIPS 140-2/140-3 cryptographic hashes for validating file and directory contents. If AIDE is installed, ensure the "sha512" rule is present on all uncommented file and directory selection lists. Exclude any log files, or files expected to change frequently, to reduce unnecessary notifications. |
CAT II | |||||
| 363 | CCI-002165 | SRG-OS-000312-GPOS-00122 | The operating system must allow operating system admins to pass information to any other operating system admin or user. | Red Hat Enterprise Linux 9 must allow operating system admins to pass information to any other operating system admin or user. | Discretionary Access Control (DAC) is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. When discretionary access control policies are implemented, subjects are not constrained with regard to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control policies is still able to operate under the less rigorous constraints of this requirement. Thus, while Mandatory Access Control imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of discretionary access control require identity-based access control, that limitation is not required for this use of discretionary access control. |
Discretionary Access Control (DAC) is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. |
Applicable - Inherently Met | Verify the operating system allows operating system admins to pass information to any other operating system admin or user. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. | Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. | CAT II | The group and other or world permission on a file allows an operating system admins to pass information to any other operating system admin or user. | The UNIX file permission model allows operating system admins to pass information to operating system admins and users. | ||||
| 364 | CCI-004066 | SRG-OS-000072-GPOS-00040 | CCE-83564-5 | The operating system must require the change of at least 50 percent of the total number of characters when passwords are changed. | Red Hat Enterprise Linux 9 must require the change of at least 8 characters when passwords are changed. | If the operating system allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. If the password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute–force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring a minimum number of different characters during password changes ensures that newly changed passwords should not resemble previously compromised ones. Note that passwords which are changed on compromised systems will still be compromised, however. |
Applicable - Configurable | Verify the operating system requires the change of at least eight of the total number of characters when passwords are changed. If it does not, this is a finding. | Verify the value of the "difok" option in "/etc/security/pwquality.conf" with the following command: $ sudo grep difok /etc/security/pwquality.conf difok = 8 If the value of "difok" is set to less than "8", or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require the change of at least 8 of the total number of characters when passwords are changed by setting the "difok" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): difok = 8 |
CAT II | |||||
| 365 | CCI-004066 | SRG-OS-000072-GPOS-00040,SRG-OS-000730-GPOS-00190 | CCE-83575-1 | The operating system must require the change of at least 50 percent of the total number of characters when passwords are changed. | Red Hat Enterprise Linux 9 must require the maximum number of repeating characters of the same character class be limited to four when passwords are changed. | If the operating system allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. If the password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Applicable - Configurable | Verify the operating system requires the change of at least eight of the total number of characters when passwords are changed. If it does not, this is a finding. | Verify the value of the "maxclassrepeat" option in "/etc/security/pwquality.conf" with the following command: $ grep maxclassrepeat /etc/security/pwquality.conf maxclassrepeat = 4 If the value of "maxclassrepeat" is set to "0", more than "4" or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require the change of the number of repeating characters of the same character class when passwords are changed by setting the "maxclassrepeat" option. Add the following line to "/etc/security/pwquality.conf" conf (or modify the line to have the required value): maxclassrepeat = 4 |
CAT II | |||||
| 366 | CCI-004066 | SRG-OS-000072-GPOS-00040 | CCE-83567-8 | The operating system must require the change of at least 50 percent of the total number of characters when passwords are changed. | Red Hat Enterprise Linux 9 must require the maximum number of repeating characters be limited to three when passwords are changed. | If the operating system allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. If the password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Applicable - Configurable | Verify the operating system requires the change of at least eight of the total number of characters when passwords are changed. If it does not, this is a finding. | Verify the value of the "maxrepeat" option in "/etc/security/pwquality.conf" with the following command: $ grep maxrepeat /etc/security/pwquality.conf maxrepeat = 3 If the value of "maxrepeat" is set to more than "3" or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require the change of the number of repeating consecutive characters when passwords are changed by setting the "maxrepeat" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): maxrepeat = 3 |
CAT II | |||||
| 367 | CCI-004066 | SRG-OS-000072-GPOS-00040 | CCE-83563-7 | The operating system must require the change of at least 50 percent of the total number of characters when passwords are changed. | Red Hat Enterprise Linux 9 must require the change of at least four character classes when passwords are changed. | If the operating system allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks. The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different. If the password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Applicable - Configurable | Verify the operating system requires the change of at least eight of the total number of characters when passwords are changed. If it does not, this is a finding. | Verify the value of the "minclass" option in "/etc/security/pwquality.conf" with the following command: $ grep minclass /etc/security/pwquality.conf minclass = 4 If the value of "minclass" is set to less than "4" or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require the change of at least 4 character classes when passwords are changed by setting the "minclass" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): minclass = 4 |
CAT II | |||||
| 368 | CCI-000154 | SRG-OS-000051-GPOS-00024 | CCE-83704-7 | The operating system must provide the capability to centrally review and analyze audit records from multiple components within the system. | Red Hat Enterprise Linux 9 must periodically flush audit records to disk to ensure that audit records are not lost. | Successful incident response and auditing relies on timely, accurate system information and analysis in order to allow the organization to identify and respond to potential incidents in a proficient manner. If the operating system does not provide the ability to centrally review the operating system logs, forensic analysis is negatively impacted. Segregation of logging data to multiple disparate computer systems is counterproductive and makes log analysis and log event alarming difficult to implement and manage, particularly when the system has multiple logging components writing to different locations or systems. To support the centralized capability, the operating system must be able to provide the information in a format that can be extracted and used, allowing the application performing the centralization of the log records to meet this requirement. |
If option "freq" isn't set to a value that requires audit records being written to disk after a threshold number is reached then audit records may be lost. | Applicable - Configurable | Verify the operating system provides the capability to centrally review and analyze audit records from multiple components within the system. If it does not, this is a finding. | Verify that audit system is configured to flush to disk after every 50 records with the following command: $ sudo grep freq /etc/audit/auditd.conf freq = 100 If "freq" isn't set to a value of "100" or greater, the value is missing, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to flush audit to disk by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": freq = 100 The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 369 | CCI-000765,CCI-004047,CCI-004046 | SRG-OS-000375-GPOS-00160,SRG-OS-000105-GPOS-00052,SRG-OS-000106-GPOS-00053,SRG-OS-000107-GPOS-00054,SRG-OS-000108-GPOS-00055 | CCE-89155-6 | The operating system must use multifactor authentication for network access to privileged accounts. | Red Hat Enterprise Linux 9 must enable certificate based smart card authentication. | Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. Factors include: 1) something a user knows (e.g., password/PIN); 2) something a user has (e.g., cryptographic identification device, token); and 3) something a user is (e.g., biometric). A privileged account is defined as an information system account with authorizations of a privileged user. Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the Internet). The DoD CAC with DoD-approved PKI is an example of multifactor authentication. |
Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. The DOD Common Access Card (CAC) with DOD-approved PKI is an example of multifactor authentication. | Applicable - Configurable | Verify the operating system uses multifactor authentication for network access to privileged accounts. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has smart cards are enabled in System Security Services Daemon (SSSD), run the following command: $ sudo grep pam_cert_auth /etc/sssd/sssd.conf pam_cert_auth = True If "pam_cert_auth" is not set to "True", the line is commented out, or the line is missing, this is a finding. |
Edit the file "/etc/sssd/sssd.conf" and add or edit the following line: pam_cert_auth = True |
CAT II | |||||
| 370 | CCI-000765,CCI-001953,CCI-001954,CCI-004046 | SRG-OS-000105-GPOS-00052,SRG-OS-000375-GPOS-00160,SRG-OS-000375-GPOS-00161,SRG-OS-000377-GPOS-00162 | CCE-83596-7 | The operating system must use multifactor authentication for network access to privileged accounts. | Red Hat Enterprise Linux 9 must have the openssl-pkcs11 package installed. | Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. Factors include: 1) something a user knows (e.g., password/PIN); 2) something a user has (e.g., cryptographic identification device, token); and 3) something a user is (e.g., biometric). A privileged account is defined as an information system account with authorizations of a privileged user. Network access is defined as access to an information system by a user (or a process acting on behalf of a user) communicating through a network (e.g., local area network, wide area network, or the Internet). The DoD CAC with DoD-approved PKI is an example of multifactor authentication. |
Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. The DOD common access card (CAC) with DOD-approved PKI is an example of multifactor authentication. | Applicable - Configurable | Verify the operating system uses multifactor authentication for network access to privileged accounts. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the openssl-pkcs11 package installed with the following command: $ sudo dnf list --installed openssl-pkcs11 Example output: openssl-pkcs.i686 0.4.11-7.el9 openssl-pkcs.x86_64 0.4.11-7.el9 If the "openssl-pkcs11" package is not installed, this is a finding. |
The openssl-pkcs11 package can be installed with the following command: $ sudo dnf install openssl-pkcs11 |
CAT II | |||||
| 371 | CCI-001665 | SRG-OS-000269-GPOS-00103 | CCE-85941-3 | In the event of a system failure, the operating system must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to mission processes. | Red Hat Enterprise Linux 9 systemd-journald service must be enabled. | Failure to a known state can address safety or security in accordance with the mission/business needs of the organization. Failure to a known secure state helps prevent a loss of confidentiality, integrity, or availability in the event of a failure of the information system or a component of the system. Preserving operating system state information helps to facilitate operating system restart and return to the operational mode of the organization with least disruption to mission/business processes. |
In the event of a system failure, Red Hat Enterprise Linux 9 must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes. | Applicable - Configurable | Verify, in the event of a system failure, the operating system preserves any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to mission processes. If it does not, this is a finding. | Verify that "systemd-journald" is active with the following command: $ systemctl is-active systemd-journald active If the systemd-journald service is not active, this is a finding. |
To enable the systemd-journald service, run the following command: $ sudo systemctl enable --now systemd-journald |
CAT II | |||||
| 372 | CCI-000187 | SRG-OS-000068-GPOS-00036 | CCE-89737-1 | The operating system must map the authenticated identity to the user or group account for PKI-based authentication. | Red Hat Enterprise Linux 9 must map the authenticated identity to the user or group account for PKI-based authentication. | Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis. | Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis. | Applicable - Configurable | Verify the operating system maps the authenticated identity to the user or group account for PKI-based authentication. If it does not, this is a finding. | Verify the certificate of the user or group is mapped to the corresponding user or group in the "sssd.conf" file with the following command: $ sudo cat /etc/sssd/sssd.conf [certmap/testing.test/rule_name] matchrule =<SAN>.*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) domains = testing.test If the certmap section does not exist, ask the system administrator (SA) to indicate how certificates are mapped to accounts. If there is no evidence of certificate mapping, this is a finding. |
Configure Red Hat Enterprise Linux 9 to map the authenticated identity to the user or group account by adding or modifying the certmap section of the "/etc/sssd/sssd.conf" file based on the following example: [certmap/testing.test/rule_name] matchrule = .*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) dmains = testing.test The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service |
CAT II | |||||
| 373 | CCI-000382,CCI-000381 | SRG-OS-000096-GPOS-00050,SRG-OS-000095-GPOS-00049 | CCE-87543-5 | The operating system must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the PPSM CAL and vulnerability assessments. | Red Hat Enterprise Linux 9 must disable the chrony daemon from acting as a server. | In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. |
Minimizing the exposure of the server functionality of the chrony daemon diminishes the attack surface. | Applicable - Configurable | Verify the operating system is configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the PPSM CAL and vulnerability assessments. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables the chrony daemon from acting as a server with the following command: $ grep -w port /etc/chrony.conf port 0 If the "port" option is not set to "0", is commented out, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the chrony daemon from acting as a server by adding/modifying the following line in the /etc/chrony.conf file: port 0 |
CAT II | |||||
| 374 | CCI-000382,CCI-000381 | SRG-OS-000096-GPOS-00050,SRG-OS-000095-GPOS-00049 | CCE-88876-8 | The operating system must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the PPSM CAL and vulnerability assessments. | Red Hat Enterprise Linux 9 must disable network management of the chrony daemon. | In order to prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by any one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business or to address authorized quality of life issues. |
Not exposing the management interface of the chrony daemon on the network diminishes the attack space. | Applicable - Configurable | Verify the operating system is configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the PPSM CAL and vulnerability assessments. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables network management of the chrony daemon with the following command: $ grep -w cmdport /etc/chrony.conf cmdport 0 If the "cmdport" option is not set to "0", is commented out, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable network management of the chrony daemon by adding/modifying the following line in the /etc/chrony.conf file: cmdport 0 |
CAT II | |||||
| 375 | CCI-000366 | SRG-OS-000480-GPOS-00230 | The operating system must limit the ability of non-privileged users to grant other users direct access to the contents of their home directories/folders. | Red Hat Enterprise Linux 9 must limit the ability of non-privileged users to grant other users direct access to the contents of their home directories/folders. | Users' home directories/folders may contain information of a sensitive nature. Non-privileged users should coordinate any sharing of information with an SA through shared resources. | Applicable - Does Not Meet | Verify the operating system limits the ability of non-privileged users to grant other users direct access to the contents of their home directories/folders. If it does not, this is a finding. | CAT II | |||||||||
| 376 | CCI-001858 | SRG-OS-000344-GPOS-00135 | The operating system must provide an immediate real-time alert to the SA and ISSO, at a minimum, of all audit failure events requiring real-time alerts. | Red Hat Enterprise Linux 9 must provide an immediate real-time alert to the SA and ISSO, at a minimum, of all audit failure events requiring real-time alerts. | It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without a real-time alert, security personnel may be unaware of an impending failure of the audit capability and system operation may be adversely affected. Alerts provide organizations with urgent messages. Real-time alerts provide these messages immediately (i.e., the time from event detection to alert occurs in seconds or less). |
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without a real-time alert, security personnel may be unaware of an impending failure of the audit capability and system operation may be adversely affected. Alerts provide organizations with urgent messages. Real-time alerts provide these messages immediately (i.e., the time from event detection to alert occurs in seconds or less). |
Applicable - Does Not Meet | Verify the operating system provides an immediate real-time alert to the SA and ISSO, at a minimum, of all audit failure events requiring real-time alerts. If it does not, this is a finding. | Red Hat Enterprise Linux 9 does not support this requirement. This is an applicable-does not meet finding. |
This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. | CAT II | Mitigate with third-party software. Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
Notification when accounts are created/modified/deleted must be provided by a third party application that will communicate that an audit record of these actions has been created. | ||||
| 377 | CCI-002235,CCI-000056 | SRG-OS-000324-GPOS-00125,SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-89538-3 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must prevent users from disabling session control mechanisms. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, Red Hat Enterprise Linux 9 must provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. | Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents users from disabling the tmux terminal multiplexer with the following command: $ grep -i tmux /etc/shells If any output is produced, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent users from disabling the tmux terminal multiplexer by editing the "/etc/shells" configuration file to remove any instances of tmux. | CAT I | |||||
| 378 | CCI-002235,CCI-002165 | SRG-OS-000312-GPOS-00122,SRG-OS-000312-GPOS-00123,SRG-OS-000324-GPOS-00125 | CCE-84110-6 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must enable kernel parameters to enforce discretionary access control on hardlinks. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
By enabling the fs.protected_hardlinks kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigates vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). | Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to enable DAC on hardlinks. Check the status of the fs.protected_hardlinks kernel parameter with the following command: $ sudo sysctl fs.protected_hardlinks fs.protected_hardlinks = 1 If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F fs.protected_hardlinks | tail -1 fs.protected_hardlinks = 1 If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enable DAC on hardlinks with the following: Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_hardlinks = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
CAT I | |||||
| 379 | CCI-002235,CCI-002165 | SRG-OS-000312-GPOS-00122,SRG-OS-000312-GPOS-00123,SRG-OS-000324-GPOS-00125 | CCE-83900-1 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must enable kernel parameters to enforce discretionary access control on symlinks. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
By enabling the fs.protected_symlinks kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the user identifier (UID) of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). | Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to enable DAC on symlinks. Check the status of the fs.protected_symlinks kernel parameter with the following command: $ sudo sysctl fs.protected_symlinks fs.protected_symlinks = 1 If "fs.protected_symlinks " is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F fs.protected_symlinks | tail -1 fs.protected_symlinks = 1 If "fs.protected_symlinks" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enable DAC on symlinks with the following: Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_symlinks = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
CAT I | |||||
| 380 | CCI-002235 | SRG-OS-000324-GPOS-00125 | CCE-83523-1 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must have the sudo package installed. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
"sudo" is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done. | Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 sudo package is installed with the following command: $ sudo dnf list --installed sudo Example output: sudo.x86_64 1.9.5p2-7.el9 If the "sudo" package is not installed, this is a finding. |
The sudo package can be installed with the following command: $ sudo dnf install sudo |
CAT I | |||||
| 381 | CCI-004895 | SRG-OS-000373-GPOS-00156,SRG-OS-000373-GPOS-00157,SRG-OS-000373-GPOS-00158 | CCE-83544-7 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must require users to reauthenticate for privilege escalation. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user reauthenticate. |
Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify that "/etc/sudoers" has no occurrences of "!authenticate" with the following command: $ sudo grep -ir '!authenticate' /etc/sudoers /etc/sudoers.d/* If any occurrences of "!authenticate" are returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow users to execute privileged actions without authenticating. Remove any occurrence of "!authenticate" found in "/etc/sudoers" file or files in the "/etc/sudoers.d" directory. $ sudo sed -i '/\!authenticate/ s/^/# /g' /etc/sudoers /etc/sudoers.d/* |
CAT I | |||||
| 382 | CCI-004895 | SRG-OS-000373-GPOS-00156,SRG-OS-000373-GPOS-00157,SRG-OS-000373-GPOS-00158 | CCE-83536-3 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must require users to provide a password for privilege escalation. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user reauthenticate. |
Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify that "/etc/sudoers" has no occurrences of "NOPASSWD" with the following command: $ sudo grep -ri nopasswd /etc/sudoers /etc/sudoers.d/* If any occurrences of "NOPASSWD" are returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to not allow users to execute privileged actions without authenticating with a password. Remove any occurrence of "NOPASSWD" found in "/etc/sudoers" file or files in the "/etc/sudoers.d" directory. $ sudo sed -i '/NOPASSWD/ s/^/# /g' /etc/sudoers /etc/sudoers.d/* |
CAT I | |||||
| 383 | CCI-004895 | SRG-OS-000373-GPOS-00156,SRG-OS-000373-GPOS-00157,SRG-OS-000373-GPOS-00158 | CCE-90029-0 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must require reauthentication when using the "sudo" command. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the organization requires the user to reauthenticate when using the "sudo" command. If the value is set to an integer less than "0", the user's time stamp will not expire and the user will not have to reauthenticate for privileged actions until the user's session is terminated. |
Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 requires reauthentication when using the "sudo" command to elevate privileges with the following command: $ sudo grep -ir 'timestamp_timeout' /etc/sudoers /etc/sudoers.d/* /etc/sudoers:Defaults timestamp_timeout=0 If results are returned from more than one file location, this is a finding. If "timestamp_timeout" is set to a negative number, is commented out, or no results are returned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to reauthenticate "sudo" commands after the specified timeout: Add the following line to "/etc/sudoers": Defaults timestamp_timeout=0 |
CAT I | |||||
| 384 | CCI-004895 | SRG-OS-000373-GPOS-00156,SRG-OS-000373-GPOS-00157,SRG-OS-000373-GPOS-00158 | CCE-85967-8 | The operating system must prevent nonprivileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. | Red Hat Enterprise Linux 9 must not be configured to bypass password requirements for privilege escalation. | Preventing non-privileged users from executing privileged functions mitigates the risk that unauthorized individuals or processes may gain unnecessary access to information or privileges. Privileged functions include, for example, establishing accounts, performing system integrity checks, or administering cryptographic key management activities. Non-privileged users are individuals that do not possess appropriate authorizations. Circumventing intrusion detection and prevention mechanisms or malicious code protection mechanisms are examples of privileged functions that require protection from non-privileged users. |
Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical the user reauthenticate. | Applicable - Configurable | Verify that the operating system prevents non-privileged users from executing privileged functions to include disabling, circumventing, or altering implemented security safeguards/countermeasures. If it does not, this is a finding. | Verify the operating system is not configured to bypass password requirements for privilege escalation with the following command: $ sudo grep pam_succeed_if /etc/pam.d/sudo If any occurrences of "pam_succeed_if" are returned, this is a finding. |
Configure the operating system to require users to supply a password for privilege escalation. Remove any occurrences of " pam_succeed_if " in the "/etc/pam.d/sudo" file. |
CAT I | |||||
| 385 | CCI-000366 | SRG-OS-000360-GPOS-00147 | The operating system must enforce dual authorization for movement and/or deletion of all audit information, when such movement or deletion is not part of an authorized automatic process. | Red Hat Enterprise Linux 9 must enforce dual authorization for movement and/or deletion of all audit information, when such movement or deletion is not part of an authorized automatic process. | An authorized user may intentionally or accidentally move or delete audit records without those specific actions being authorized. All bulk manipulation of audit information must be authorized via automatic processes. Any manual manipulation of audit information must require dual authorization. Dual authorization mechanisms require the approval of two authorized individuals to execute. |
Applicable - Does Not Meet | Verify the operating system enforces dual authorization for movement and/or deletion of all audit information, when such movement or deletion is not part of an authorized automatic process. If it does not, this is a finding. | Red Hat Enterprise Linux 9 does not support this requirement. This is an applicable-does not meet finding. |
This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. |
CAT II | The following items mitigate this risk by protecting the audit logs and tools from unauthorized access. SRG-OS-000206-GPOS-00084 or mitigate with third-party software. Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
This is a procedural-only requirement that is not enforced by the OS. | |||||
| 386 | CCI-001387,CCI-001384,CCI-000048,CCI-001386,CCI-001388,CCI-001385 | SRG-OS-000023-GPOS-00006,SRG-OS-000228-GPOS-00088 | CCE-90807-9 | Any publically accessible connection to the operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. | Red Hat Enterprise Linux 9 must display the Standard Mandatory DOD Notice and Consent Banner before granting local or remote access to the system via a SSH logon. | Display of a standardized and approved use notification before granting access to the publicly accessible operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've readconsent to terms in IS user agreem't." |
The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution. | Applicable - Configurable | Verify any publically accessible connection to the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If it does not, this is a finding. |
Verify that any SSH connection to the operating system displays the Standard Mandatory DOD Notice and Consent Banner before granting access to the system. Check for the location of the banner file being used with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*banner' banner /etc/issue This command will return the banner keyword and the name of the file that contains the SSH banner (in this case "/etc/issue"). If the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to display the Standard Mandatory DOD Notice and Consent Banner before granting access to the system via ssh. Edit the "/etc/ssh/sshd_config" file to uncomment the banner keyword and configure it to point to a file that will contain the logon banner (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor). An example configuration line is: Banner /etc/issue |
CAT II | |||||
| 387 | CCI-001387,CCI-001384,CCI-000048,CCI-001386,CCI-001388,CCI-001385 | SRG-OS-000023-GPOS-00006,SRG-OS-000228-GPOS-00088 | CCE-83557-9 | Any publically accessible connection to the operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. | Red Hat Enterprise Linux 9 must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system via a command line user logon. | Display of a standardized and approved use notification before granting access to the publicly accessible operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've readconsent to terms in IS user agreem't." |
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist. |
Applicable - Configurable | Verify any publically accessible connection to the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If it does not, this is a finding. |
Verify Red Hat Enterprise Linux 9 displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the operating system via a command line user logon. Check that a banner is displayed at the command line login screen with the following command: $ sudo cat /etc/issue If the banner is set correctly it will return the following text: “You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.” If the banner text does not match the Standard Mandatory DoD Notice and Consent Banner exactly, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system via command line logon. Edit the "/etc/issue" file to replace the default text with the Standard Mandatory DoD Notice and Consent Banner. The DoD-required text is: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." |
CAT II | |||||
| 388 | CCI-001387,CCI-001384,CCI-000048,CCI-001386,CCI-001388,CCI-001385 | SRG-OS-000023-GPOS-00006,SRG-OS-000228-GPOS-00088 | CCE-87599-7 | Any publically accessible connection to the operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. | Red Hat Enterprise Linux 9 must prevent a user from overriding the banner-message-enable setting for the graphical user interface. | Display of a standardized and approved use notification before granting access to the publicly accessible operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've readconsent to terms in IS user agreem't." |
Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist. |
Applicable - Configurable | Verify any publically accessible connection to the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If it does not, this is a finding. |
Verify Red Hat Enterprise Linux 9 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep banner-message-enable /etc/dconf/db/local.d/* /org/gnome/login-screen/banner-message-enable If the output is not "/org/gnome/login-screen/banner-message-enable", the line is commented out, or the line is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding the banner setting for graphical user interfaces. Create a database to contain the system-wide graphical user logon settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: banner-message-enable Run the following command to update the database: $ sudo dconf update |
CAT II | |||||
| 389 | CCI-002385 | SRG-OS-000420-GPOS-00186 | CCE-86394-4 | The operating system must protect against or limit the effects of Denial of Service (DoS) attacks by ensuring the operating system is implementing rate-limiting measures on impacted network interfaces. | Red Hat Enterprise Linux 9 must protect against or limit the effects of Denial of Service (DoS) attacks by ensuring rate-limiting measures on impacted network interfaces are implemented. | DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks. |
DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of Red Hat Enterprise Linux 9 to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exists to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks. |
Applicable - Configurable | Verify the operating system protects against or limits the effects of Denial of Service (DoS) attacks by ensuring the operating system is implementing rate-limiting measures on impacted network interfaces. If it does not, this is a finding. | Verify "nftables" is configured to allow rate limits on any connection to the system with the following command: $ sudo grep -i firewallbackend /etc/firewalld/firewalld.conf # FirewallBackend FirewallBackend=nftables If the "nftables" is not set as the "FirewallBackend" default, this is a finding. |
Configure "nftables" to be the default "firewallbackend" for "firewalld" by adding or editing the following line in "etc/firewalld/firewalld.conf": FirewallBackend=nftables Establish rate-limiting rules based on organization-defined types of DoS attacks on impacted network interfaces. |
CAT II | |||||
| 390 | CCI-000056 | SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-90171-0 | The operating system must retain a users session lock until that user reestablishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 9 must enable a user session lock until that user re-establishes access using established identification and authentication procedures for command line sessions. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock shall remain in place until the user re-authenticates. No other activity aside from re-authentication shall unlock the system. |
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, Red Hat Enterprise Linux 9 must provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. The "tmux" package allows for a session lock to be implemented and configured. However, the session lock is implemented by an external command. The "tmux" default configuration does not contain an effective session lock. |
Applicable - Configurable | Verify the operating system retains a user's session lock until that user reestablishes access using established identification and authentication procedures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 enables the user to initiate a session lock with the following command: $ grep lock-command /etc/tmux.conf set -g lock-command vlock If the "lock-command" is not set in the global settings to call "vlock", this is a finding. |
Configure Red Hat Enterprise Linux 9 to allow a user to initiate a sessions lock by adding the following line to the file "/etc/tmux.conf": set -g lock-command vlock |
CAT I | |||||
| 391 | CCI-000057,CCI-000056 | SRG-OS-000030-GPOS-00011,SRG-OS-000028-GPOS-00009 | CCE-83599-1 | The operating system must retain a users session lock until that user reestablishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 9 must have the tmux package installed. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock shall remain in place until the user re-authenticates. No other activity aside from re-authentication shall unlock the system. |
Tmux is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Red Hat endorses tmux as the recommended session controlling package. | Applicable - Configurable | Verify the operating system retains a user's session lock until that user reestablishes access using established identification and authentication procedures. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the tmux package installed with the following command: $ sudo dnf list --installed tmux Example output: tmux.x86_64 3.2a-4.el9 If the "tmux" package is not installed, this is a finding. |
The tmux package can be installed with the following command: $ sudo dnf install tmux |
CAT I | |||||
| 392 | CCI-000057,CCI-000056 | SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-86452-0 | The operating system must retain a users session lock until that user reestablishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 9 must prevent a user from overriding the disabling of the graphical user smart card removal action. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock shall remain in place until the user re-authenticates. No other activity aside from re-authentication shall unlock the system. |
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, Red Hat Enterprise Linux 9 needs to provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. |
Applicable - Configurable | Verify the operating system retains a user's session lock until that user reestablishes access using established identification and authentication procedures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 disables ability of the user to override the smart card removal action setting. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that the removal action setting is locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep 'removal-action' /etc/dconf/db/local.d/locks/* /org/gnome/settings-daemon/peripherals/smartcard/removal-action If the command does not return at least the example result, this is a finding. |
Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user override of the smart card removal action: /org/gnome/settings-daemon/peripherals/smartcard/removal-action Then update the dconf system databases: $ sudo dconf update |
CAT I | |||||
| 393 | CCI-000057,CCI-000056 | SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-89302-4 | The operating system must retain a users session lock until that user reestablishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 9 must prevent a user from overriding the screensaver lock-enabled setting for the graphical user interface. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock shall remain in place until the user re-authenticates. No other activity aside from re-authentication shall unlock the system. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. |
Applicable - Configurable | Verify the operating system retains a user's session lock until that user reestablishes access using established identification and authentication procedures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-enabled /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-enabled If the command does not return at least the example result, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/screensaver/lock-enabled |
CAT I | |||||
| 394 | CCI-000056,CCI-000057 | SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-90150-4 | The operating system must retain a users session lock until that user reestablishes access using established identification and authentication procedures. | Red Hat Enterprise Linux 9 must prevent a user from overriding the screensaver lock-enabled setting for the graphical user interface. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock shall remain in place until the user re-authenticates. No other activity aside from re-authentication shall unlock the system. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. |
Applicable - Configurable | Verify the operating system retains a user's session lock until that user reestablishes access using established identification and authentication procedures. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from non-privileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-enabled /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-enabled If the command does not return at least the example result, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent non-privileged users from modifying it: /org/gnome/desktop/screensaver/lock-enabled |
CAT I | |||||
| 395 | CCI-001493 | SRG-OS-000256-GPOS-00097,SRG-OS-000257-GPOS-00098,SRG-OS-000258-GPOS-00099 | CCE-86228-4 | The operating system must protect audit tools from unauthorized deletion. | Red Hat Enterprise Linux 9 audit tools must have a mode of 0755 or less permissive. | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user has in order to make access decisions regarding the deletion of audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Red Hat Enterprise Linux 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Applicable - Configurable | Verify the operating system protects audit tools from unauthorized deletion. If it does not, this is a finding. | Verify the audit tools have a mode of "0755" or less with the following command: $ stat -c "%a %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules 755 /sbin/auditctl 755 /sbin/aureport 755 /sbin/ausearch 750 /sbin/autrace 755 /sbin/auditd 755 /sbin/rsyslogd 755 /sbin/augenrules If any of the audit tool files have a mode more permissive than "0755", this is a finding. |
Configure the audit tools to have a mode of "0755" by running the following command: $ sudo chmod 0755 [audit_tool] Replace "[audit_tool]" with each audit tool that has a more permissive mode than 0755. |
CAT II | |||||
| 396 | CCI-001493 | SRG-OS-000256-GPOS-00097,SRG-OS-000257-GPOS-00098,SRG-OS-000258-GPOS-00099 | CCE-86263-1 | The operating system must protect audit tools from unauthorized deletion. | Red Hat Enterprise Linux 9 audit tools must be owned by root. | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user has in order to make access decisions regarding the deletion of audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Red Hat Enterprise Linux 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Applicable - Configurable | Verify the operating system protects audit tools from unauthorized deletion. If it does not, this is a finding. | Verify the audit tools are owned by "root" with the following command: $ sudo stat -c "%U %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any audit tools do not have an owner of "root", this is a finding. |
Configure the audit tools to be owned by "root" by running the following command: $ sudo chown root [audit_tool] Replace "[audit_tool]" with each audit tool not owned by "root". |
CAT II | |||||
| 397 | CCI-001493 | SRG-OS-000256-GPOS-00097,SRG-OS-000257-GPOS-00098,SRG-OS-000258-GPOS-00099 | CCE-86240-9 | The operating system must protect audit tools from unauthorized deletion. | Red Hat Enterprise Linux 9 audit tools must be group-owned by root. | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user has in order to make access decisions regarding the deletion of audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data; therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Red Hat Enterprise Linux 9 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user enjoys, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. |
Applicable - Configurable | Verify the operating system protects audit tools from unauthorized deletion. If it does not, this is a finding. | Verify the audit tools are group owned by "root" with the following command: $ sudo stat -c "%G %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any audit tools do not have a group owner of "root", this is a finding. |
Configure the audit tools to be group-owned by "root" by running the following command: $ sudo chgrp root [audit_tool] Replace "[audit_tool]" with each audit tool not group-owned by "root". |
CAT II | |||||
| 398 | CCI-002165,CCI-004895 | SRG-OS-000373-GPOS-00156,SRG-OS-000312-GPOS-00123 | CCE-90085-2 | The operating system must allow operating system admins to grant their privileges to other operating system admins. | Red Hat Enterprise Linux 9 must restrict the use of the "su" command. | Discretionary Access Control (DAC) is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. When discretionary access control policies are implemented, subjects are not constrained with regard to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control policies is still able to operate under the less rigorous constraints of this requirement. Thus, while Mandatory Access Control imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of discretionary access control require identity-based access control, that limitation is not required for this use of discretionary access control. |
The "su" program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such commands is considered a good security practice. | Applicable - Configurable | Verify the operating system allows operating system admins to grant their privileges to other operating system admins. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 requires uses to be members of the "wheel" group with the following command: $ grep pam_wheel /etc/pam.d/su auth required pam_wheel.so use_uid If a line for "pam_wheel.so" does not exist, or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require users to be in the "wheel" group to run "su" command. In file "/etc/pam.d/su", uncomment the following line: "#auth required pam_wheel.so use_uid" $ sed '/^[[:space:]]*#[[:space:]]*auth[[:space:]]\+required[[:space:]]\+pam_wheel\.so[[:space:]]\+use_uid$/s/^[[:space:]]*#//' -i /etc/pam.d/su If necessary, create a "wheel" group and add administrative users to the group. |
CAT II | |||||
| 399 | CCI-001954,CCI-004046 | SRG-OS-000375-GPOS-00160,SRG-OS-000377-GPOS-00162 | CCE-87088-1 | The operating system must electronically verify Personal Identity Verification (PIV) credentials. | Red Hat Enterprise Linux 9 must implement certificate status checking for multifactor authentication. | The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. DoD has mandated the use of the CAC to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. |
Using an authentication device, such as a DoD Common Access Card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, credentials stored on the authentication device will not be affected. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DoD CAC. Red Hat Enterprise Linux 9 includes multiple options for configuring certificate status checking, but for this requirement focuses on the System Security Services Daemon (SSSD). By default, sssd performs Online Certificate Status Protocol (OCSP) checking and certificate verification using a sha256 digest function. |
Applicable - Configurable | Verify the operating system electronically verifies Personal Identity Verification (PIV) credentials. If it does not, this is a finding. | Verify the operating system implements Online Certificate Status Protocol (OCSP) and is using the proper digest value on the system with the following command: $ sudo grep certificate_verification /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf | grep -v "^#" certificate_verification = ocsp_dgst=sha512 If the certificate_verification line is missing from the [sssd] section, or is missing "ocsp_dgst=sha512", ask the administrator to indicate what type of multifactor authentication is being utilized and how the system implements certificate status checking. If there is no evidence of certificate status checking being used, this is a finding. |
Configure Red Hat Enterprise Linux 9 to implement certificate status checking for multifactor authentication. Review the "/etc/sssd/conf.d/certificate_verification.conf" file to determine if the system is configured to prevent OCSP or certificate verification. Add the following line to the "/etc/sssd/conf.d/certificate_verification.conf" file: certificate_verification = ocsp_dgst=sha512 Set the correct ownership and permissions on the "/etc/sssd/conf.d/certificate_verification.conf" file by running these commands: $ sudo chown root:root "/etc/sssd/conf.d/certificate_verification.conf" $ sudo chmod 600 "/etc/sssd/conf.d/certificate_verification.conf" The "sssd" service must be restarted for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service |
CAT II | |||||
| 400 | CCI-000054 | SRG-OS-000027-GPOS-00008 | CCE-83641-1 | The operating system must limit the number of concurrent sessions to ten for all accounts and/or account types. | Red Hat Enterprise Linux 9 must limit the number of concurrent sessions to ten for all accounts and/or account types. | Operating system management includes the ability to control the number of users and user sessions that utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to DoS attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system. |
Operating system management includes the ability to control the number of users and user sessions that utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to DoS attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based on mission needs and the operational environment for each system. |
Applicable - Configurable | Verify the operating system limits the number of concurrent sessions to ten for all accounts and/or account types. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 limits the number of concurrent sessions to "10" for all accounts and/or account types with the following command: $ grep -r -s maxlogins /etc/security/limits.conf /etc/security/limits.d/*.conf /etc/security/limits.conf:* hard maxlogins 10 This can be set as a global domain (with the * wildcard) but may be set differently for multiple domains. If the "maxlogins" item is missing, commented out, or the value is set greater than "10" and is not documented with the Information System Security Officer (ISSO) as an operational requirement for all domains that have the "maxlogins" item assigned, this is a finding. |
Configure Red Hat Enterprise Linux 9 to limit the number of concurrent sessions to "10" for all accounts and/or account types. Add the following line to the top of the /etc/security/limits.conf or in a ".conf" file defined in /etc/security/limits.d/ : * hard maxlogins 10 |
CAT III | |||||
| 401 | CCI-000172,CCI-000130,CCI-000135,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085 | CCE-89564-9 | The operating system must generate audit records containing the full-text recording of privileged commands. | Red Hat Enterprise Linux 9 must audit all uses of the mount command. | Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system generates audit records containing the full-text recording of privileged commands. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "mount" command with the following command: $ sudo auditctl -l | grep /usr/bin/mount -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "mount" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 402 | CCI-000135,CCI-000172,CCI-002884 | SRG-OS-000042-GPOS-00020,SRG-OS-000392-GPOS-00172,SRG-OS-000471-GPOS-00215,SRG-APP-000499-CTR-001255,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-88512-9 | The operating system must generate audit records containing the full-text recording of privileged commands. | Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. |
Applicable - Configurable | Verify the operating system generates audit records containing the full-text recording of privileged commands. If it does not, this is a finding. | CAT II | |||||||||
| 403 | CCI-000172,CCI-000130,CCI-000169,CCI-002884 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215,SRG-APP-000029-CTR-000085 | CCE-83762-5 | The operating system must generate audit records containing the full-text recording of privileged commands. | Red Hat Enterprise Linux 9 must audit all uses of umount system calls. | Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. |
Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system generates audit records containing the full-text recording of privileged commands. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "umount" command with the following command: $ sudo auditctl -l | grep umount -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount If the command does not return an audit rule for "umount" or any of the lines returned are commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "umount" command by adding or updating the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount The audit daemon must be restarted for the changes to take effect. |
CAT II | |||||
| 404 | CCI-000132,CCI-001851 | SRG-OS-000039-GPOS-00017,SRG-OS-000342-GPOS-00133,SRG-OS-000479-GPOS-00224 | CCE-83686-6 | The operating system must, at a minimum, off-load audit data from interconnected systems in real time and off-load audit data from standalone systems weekly. | Red Hat Enterprise Linux 9 must label all off-loaded audit logs before sending them to the central log server. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
Enriched logging is needed to determine who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult. When audit logs are not labeled before they are sent to a central log server, the audit data will not be able to be analyzed and tied back to the correct system. |
Applicable - Configurable | Verify the operating system, at a minimum, off-loads interconnected systems in real time and off-loads standalone systems weekly. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 Audit Daemon is configured to label all off-loaded audit logs, with the following command: $ sudo grep name_format /etc/audit/auditd.conf name_format = hostname If the "name_format" option is not "hostname", "fqd", or "numeric", or the line is commented out, this is a finding. |
Edit the /etc/audit/auditd.conf file and add or update the "name_format" option: name_format = hostname The audit daemon must be restarted for changes to take effect. |
CAT II | |||||
| 405 | CCI-001851 | SRG-OS-000342-GPOS-00133,SRG-OS-000479-GPOS-00224 | CCE-87901-5 | The operating system must, at a minimum, off-load audit data from interconnected systems in real time and off-load audit data from standalone systems weekly. | Red Hat Enterprise Linux 9 must take appropriate action when the internal event queue is full. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
The audit system should have an action setup in the event the internal event queue becomes full so that no data is lost. Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. |
Applicable - Configurable | Verify the operating system, at a minimum, off-loads interconnected systems in real time and off-loads standalone systems weekly. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 audit system is configured to take an appropriate action when the internal event queue is full: $ sudo grep -i overflow_action /etc/audit/auditd.conf overflow_action = syslog If the value of the "overflow_action" option is not set to "syslog", "single", "halt" or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the transfer of the audit logs being offloaded to another system or media takes appropriate action if the internal event queue becomes full, this is a finding. |
Edit the /etc/audit/auditd.conf file and add or update the "overflow_action" option: overflow_action = syslog The audit daemon must be restarted for changes to take effect. |
CAT II | |||||
| 406 | CCI-001851 | SRG-OS-000342-GPOS-00133,SRG-OS-000479-GPOS-00224 | CCE-86871-1 | The operating system must, at a minimum, off-load audit data from interconnected systems in real time and off-load audit data from standalone systems weekly. | Red Hat Enterprise Linux 9 must authenticate the remote logging server for offloading audit logs via rsyslog. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. Red Hat Enterprise Linux 9 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS and DTLS protocols) creates a method to securely encrypt and offload auditing. "Rsyslog" supported authentication modes include: anon - anonymous authentication x509/fingerprint - certificate fingerprint authentication x509/certvalid - certificate validation only x509/name - certificate validation and subject name authentication |
Applicable - Configurable | Verify the operating system, at a minimum, off-loads interconnected systems in real time and off-loads standalone systems weekly. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 authenticates the remote logging server for offloading audit logs with the following command: $ sudo grep -i '$ActionSendStreamDriverAuthMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverAuthMode x509/name If the value of the "$ActionSendStreamDriverAuthMode" option is not set to "x509/name" or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the transfer of the audit logs being offloaded to another system or media is encrypted, this is a finding. |
Configure Red Hat Enterprise Linux 9 to authenticate the remote logging server for offloading audit logs by setting the following option in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $ActionSendStreamDriverAuthMode x509/name |
CAT II | |||||
| 407 | CCI-001851 | SRG-OS-000342-GPOS-00133,SRG-OS-000479-GPOS-00224 | CCE-90191-8 | The operating system must, at a minimum, off-load audit data from interconnected systems in real time and off-load audit data from standalone systems weekly. | Red Hat Enterprise Linux 9 must encrypt the transfer of audit records offloaded onto a different system or media from the system being audited via rsyslog. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. Red Hat Enterprise Linux 9 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS and DTLS protocols) creates a method to securely encrypt and offload auditing. "Rsyslog" supported authentication modes include: anon - anonymous authentication x509/fingerprint - certificate fingerprint authentication x509/certvalid - certificate validation only x509/name - certificate validation and subject name authentication |
Applicable - Configurable | Verify the operating system, at a minimum, off-loads interconnected systems in real time and off-loads standalone systems weekly. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 encrypts audit records offloaded onto a different system or media from the system being audited via rsyslog with the following command: $ sudo grep -i '$ActionSendStreamDriverMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverMode 1 If the value of the "$ActionSendStreamDriverMode" option is not set to "1" or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to encrypt offloaded audit records via rsyslog by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $ActionSendStreamDriverMode 1 |
CAT II | |||||
| 408 | CCI-001851 | SRG-OS-000342-GPOS-00133,SRG-OS-000479-GPOS-00224 | CCE-86782-0 | The operating system must, at a minimum, off-load audit data from interconnected systems in real time and off-load audit data from standalone systems weekly. | Red Hat Enterprise Linux 9 must encrypt via the gtls driver the transfer of audit records offloaded onto a different system or media from the system being audited via rsyslog. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. Red Hat Enterprise Linux 9 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS and DTLS protocols) creates a method to securely encrypt and offload auditing. |
Applicable - Configurable | Verify the operating system, at a minimum, off-loads interconnected systems in real time and off-loads standalone systems weekly. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 uses the gtls driver to encrypt audit records offloaded onto a different system or media from the system being audited with the following command: $ sudo grep -i '$DefaultNetstreamDriver' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$DefaultNetstreamDriver gtls If the value of the "$DefaultNetstreamDriver" option is not set to "gtls" or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use the gtls driver to encrypt offloaded audit records by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $DefaultNetstreamDriver gtls |
CAT II | |||||
| 409 | CCI-004922 | SRG-OS-000785-GPOS-00250 | The operating system must synchronize system clocks within and between systems or system components. | Red Hat Enterprise Linux 9 must synchronize system clocks within and between systems or system components. | Time synchronization of system clocks is essential for the correct execution of many system services, including identification and authentication processes that involve certificates and time-of-day restrictions as part of access control. Denial of service or failure to deny expired credentials may result without properly synchronized clocks within and between systems and system components. Time is commonly expressed in Coordinated Universal Time (UTC), a modern continuation of Greenwich Mean Time (GMT), or local time with an offset from UTC. The granularity of time measurements refers to the degree of synchronization between system clocks and reference clocks, such as clocks synchronizing within hundreds of milliseconds or tens of milliseconds. Organizations may define different time granularities for system components. Time service can be critical to other security capabilities—such as access control and identification and authentication—depending on the nature of the mechanisms used to support the capabilities. | pending | Verify the operating system is configured to synchronize system clocks within and between systems or system components. If the operating system is not configured to synchronize system clocks within and between systems or system components, this is a finding. |
CAT II | |||||||||
| 410 | CCI-004961 | SRG-OS-000805-GPOS-00260 | CCE-83456-4 | The operating system must employ automated patch management tools to facilitate flaw remediation to the organization-defined system components. | Red Hat Enterprise Linux 9 must configure dnf-automatic to Install Available Updates Automatically. | Using automated tools to support patch management helps to ensure the timeliness and completeness of system patching operations. | Using automated tools to support patch management helps to ensure the timeliness and completeness of system patching operations. |
Applicable - Configurable | Verify the operating system is configured to employ automated patch management tools to facilitate flaw remediation to the organization-defined system components. If the operating system is not configured to employ automated patch management tools to facilitate flaw remediation to the organization-defined system components, this is a finding. |
To verify that packages comprising the available updates will be automatically installed by dnf-automatic, run the following command: $ sudo grep apply_updates /etc/dnf/automatic.conf The output should return the following: apply_updates = yes If apply_updates line is missing, commented out, or not set to "yes", this is a finding. |
Configure Red Hat Enterprise Linux 9 to automatically apply updates. Edit the file "/etc/dnf/automatic.conf" and add the following: apply_updates = yes |
CAT II | |||||
| 411 | CCI-004961 | SRG-OS-000191-GPOS-00080 | CCE-83454-9 | The operating system must employ automated patch management tools to facilitate flaw remediation to the organization-defined system components. | Red Hat Enterprise Linux 9 must have the dnf-automatic package installed. | Using automated tools to support patch management helps to ensure the timeliness and completeness of system patching operations. | "dnf-automatic" is a package designed to allow automatic updates of Red Hat Enterprise Linux 9. | Applicable - Configurable | Verify the operating system is configured to employ automated patch management tools to facilitate flaw remediation to the organization-defined system components. If the operating system is not configured to employ automated patch management tools to facilitate flaw remediation to the organization-defined system components, this is a finding. |
Verify that Red Hat Enterprise Linux 9 dnf-automatic package is installed with the following command: $ sudo dnf list --installed dnf-automatic Example output: dnf-automatic.x86_64 4.20.0-6.el10 If the "dnf-automatic" package is not installed, this is a finding. |
The dnf-automatic package can be installed with the following command: $ sudo dnf install dnf-automatic |
CAT II | |||||
| 412 | CCI-004063 | SRG-OS-000720-GPOS-00170 | The operating system must for password-based authentication, require immediate selection of a new password upon account recovery. | Red Hat Enterprise Linux 9 must for password-based authentication, require immediate selection of a new password upon account recovery. | Password-based authentication applies to passwords regardless of whether they are used in single-factor or multifactor authentication. Long passwords or passphrases are preferable over shorter passwords. Enforced composition rules provide marginal security benefits while decreasing usability. However, organizations may choose to establish certain rules for password generation (e.g., minimum character length for long passwords) under certain circumstances and can enforce this requirement in IA-5(1)(h). Account recovery can occur, for example, in situations when a password is forgotten. Cryptographically protected passwords include salted one-way cryptographic hashes of passwords. The list of commonly used, compromised, or expected passwords includes passwords obtained from previous breach corpuses, dictionary words, and repetitive or sequential characters. The list includes context-specific words, such as the name of the service, username, and derivatives thereof. | pending | Verify the operating system is configured to require immediate selection of a new password upon account recovery for password-based authentication. If the operating system is not configured to require immediate selection of a new password upon account recovery for password-based authentication, this is a finding. |
CAT II | |||||||||
| 413 | CCI-001849,CCI-001464 | SRG-OS-000037-GPOS-00015,SRG-OS-000042-GPOS-00020,SRG-OS-000062-GPOS-00031,SRG-OS-000254-GPOS-00095,SRG-OS-000341-GPOS-00132,SRG-OS-000392-GPOS-00172,SRG-OS-000462-GPOS-00206,SRG-OS-000471-GPOS-00215 | CCE-83652-8 | The operating system must allocate audit record storage capacity to store at least one week's worth of audit records, when audit records are not immediately sent to a central audit record storage facility. | Red Hat Enterprise Linux 9 must allocate an audit_backlog_limit of sufficient size to capture processes that start prior to the audit daemon. | In order to ensure operating systems have a sufficient storage capacity in which to write the audit logs, operating systems need to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of the operating system. |
Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). Allocating an audit_backlog_limit of sufficient size is critical in maintaining a stable boot process. With an insufficient limit allocated, the system is susceptible to boot failures and crashes. |
Applicable - Configurable | Verify the operating system allocates audit record storage capacity to store at least one week's worth of audit records, when audit records are not immediately sent to a central audit record storage facility. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 allocates a sufficient audit_backlog_limit to capture processes that start prior to the audit daemon with the following command: $ sudo grubby --info=ALL | grep args | grep -v 'audit_backlog_limit=8192' If the command returns any outputs, and audit_backlog_limit is less than "8192", this is a finding. |
Configure Red Hat Enterprise Linux 9 to allocate sufficient audit_backlog_limit to capture processes that start prior to the audit daemon with the following command: $ sudo grubby --update-kernel=ALL --args=audit_backlog_limit=8192 |
CAT III | |||||
| 414 | CCI-001849,CCI-001851 | SRG-OS-000341-GPOS-00132,SRG-OS-000342-GPOS-00133 | CCE-88173-0 | The operating system must allocate audit record storage capacity to store at least one week's worth of audit records, when audit records are not immediately sent to a central audit record storage facility. | Red Hat Enterprise Linux 9 must allocate audit record storage capacity to store at least one week's worth of audit records. | In order to ensure operating systems have a sufficient storage capacity in which to write the audit logs, operating systems need to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of the operating system. |
To ensure Red Hat Enterprise Linux 9 systems have a sufficient storage capacity in which to write the audit logs, Red Hat Enterprise Linux 9 needs to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of Red Hat Enterprise Linux 9. |
Applicable - Configurable | Verify the operating system allocates audit record storage capacity to store at least one week's worth of audit records, when audit records are not immediately sent to a central audit record storage facility. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 allocates audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. Note: The partition size needed to capture a week of audit records is based on the activity level of the system and the total storage capacity available. Typically 10.0 GB of storage space for audit records should be sufficient. Determine which partition the audit records are being written to with the following command: $ sudo grep log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Check the size of the partition that audit records are written to with the following command and verify whether it is sufficiently large: # df -h /var/log/audit/ /dev/sda2 24G 10.4G 13.6G 43% /var/log/audit If the audit record partition is not allocated for sufficient storage capacity, this is a finding. |
Allocate enough storage capacity for at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. If audit records are stored on a partition made specifically for audit records, resize the partition with sufficient space to contain one week of audit records. If audit records are not stored on a partition made specifically for audit records, a new partition with sufficient space will need be to be created. |
CAT III | |||||
| 415 | CCI-000135,CCI-000764,CCI-000804 | SRG-OS-000104-GPOS-00051,SRG-OS-000121-GPOS-00062 | CCE-88493-2 | The operating system must uniquely identify and must authenticate organizational users (or processes acting on behalf of organizational users). | Red Hat Enterprise Linux 9 duplicate User IDs (UIDs) must not exist for interactive users. | To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity. |
To ensure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. | Applicable - Configurable | Verify the operating system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users). If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 contains no duplicate UIDs for interactive users with the following command: $ sudo awk -F ":" 'list[$3]++{print $1, $3}' /etc/passwd If output is produced and the accounts listed are interactive user accounts, this is a finding. |
Edit the file "/etc/passwd" and provide each interactive user account that has a duplicate UID with a unique UID. | CAT II | |||||
| 416 | CCI-000764 | SRG-OS-000104-GPOS-00051 | CCE-86043-7 | The operating system must uniquely identify and must authenticate organizational users (or processes acting on behalf of organizational users). | Red Hat Enterprise Linux 9 groups must have unique Group ID (GID). | To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity. |
To ensure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. | Applicable - Configurable | Verify the operating system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users). If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 contains no duplicate GIDs for interactive users with the following command: $ cut -d : -f 3 /etc/group | uniq -d If the system has duplicate GIDs, this is a finding. |
Edit the file "/etc/group" and provide each group that has a duplicate GID with a unique GID. | CAT II | |||||
| 417 | CCI-000764 | SRG-OS-000104-GPOS-00051 | CCE-83613-0 | The operating system must uniquely identify and must authenticate organizational users (or processes acting on behalf of organizational users). | All Red Hat Enterprise Linux 9 interactive users must have a primary group that exists. | To assure accountability and prevent unauthenticated access, organizational users must be identified and authenticated to prevent potential misuse and compromise of the system. Organizational users include organizational employees or individuals the organization deems to have equivalent status of employees (e.g., contractors). Organizational users (and processes acting on behalf of users) must be uniquely identified and authenticated to all accesses, except for the following: 1) Accesses explicitly identified and documented by the organization. Organizations document specific user actions that can be performed on the information system without identification or authentication; and 2) Accesses that occur through authorized use of group authenticators without individual authentication. Organizations may require unique identification of individuals in group accounts (e.g., shared privilege accounts) or for detailed accountability of individual activity. |
If a user is assigned the Group Identifier (GID) of a group that does not exist on the system, and a group with the GID is subsequently created, the user may have unintended rights to any files associated with the group. | Applicable - Configurable | Verify the operating system uniquely identifies and authenticates organizational users (or processes acting on behalf of organizational users). If it does not, this is a finding. | Verify that all Red Hat Enterprise Linux 9 interactive users have a valid GID. Check that the interactive users have a valid GID with the following command: $ sudo pwck -qr If the system has any interactive users with duplicate GIDs, this is a finding. |
Configure the system so that all GIDs are referenced in "/etc/passwd" are defined in "/etc/group". Edit the file "/etc/passwd" and ensure that every user's GID is a valid GID. |
CAT II | |||||
| 418 | CCI-000015 | SRG-OS-000001-GPOS-00001 | The operating system must provide automated mechanisms for supporting account management functions. | Red Hat Enterprise Linux 9 must provide automated mechanisms for supporting account management functions. | Enterprise environments make account management challenging and complex. A manual process for account management functions adds the risk of a potential oversight or other errors. A comprehensive account management process that includes automation helps to ensure accounts designated as requiring attention are consistently and promptly addressed. Examples include, but are not limited to, using automation to take action on multiple accounts designated as inactive, suspended or terminated, or by disabling accounts located in non-centralized account stores such as multiple servers. This requirement applies to all account types, including individual/user, shared, group, system, guest/anonymous, emergency, developer/manufacturer/vendor, temporary, and service. The automated mechanisms may reside within the operating system itself or may be offered by other infrastructure providing automated account management capabilities. Automated mechanisms may be composed of differing technologies that, when placed together, contain an overall automated mechanism supporting an organization's automated account management requirements. Account management functions include: assigning group or role membership; identifying account type; specifying user access authorizations (i.e., privileges); account removal, update, or termination; and administrative alerts. The use of automated mechanisms can include, for example: using email or text messaging to automatically notify account managers when users are terminated or transferred; using the information system to monitor account usage; and using automated telephonic notification to report atypical system account usage. |
Enterprise environments make account management challenging and complex. A manual process for account management functions adds the risk of a potential oversight or other errors. A comprehensive account management process that includes automation helps to ensure accounts designated as requiring attention are consistently and promptly addressed. Examples include, but are not limited to, using automation to take action on multiple accounts designated as inactive, suspended, or terminated, or by disabling accounts located in non-centralized account stores such as multiple servers. This requirement applies to all account types, including individual/user, shared, group, system, guest/anonymous, emergency, developer/manufacturer/vendor, temporary, and service. The automated mechanisms may reside within the operating system itself or may be offered by another infrastructure providing automated account management capabilities. Automated mechanisms may be composed of differing technologies that, when placed together, contain an overall automated mechanism supporting an organization's automated account management requirements. Account management functions include: assigning group or role membership; identifying account type; specifying user access authorizations (i.e., privileges); account removal, update, or termination; and administrative alerts. The use of automated mechanisms can include, for example: using email or text messaging to automatically notify account managers when users are terminated or transferred; using the information system to monitor account usage; and using automated telephonic notification to report atypical system account usage. |
Applicable - Does Not Meet | Verify the operating system provides automated mechanisms for supporting account management functions. If it does not, this is a finding. | Red Hat Enterprise Linux 9 does not support this requirement. This is an applicable-does not meet finding. |
This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. |
CAT II | Mitigate with third-party software. Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
Mitigate with third-party software. As noted in the vulnerability discussion, "The automated mechanisms may reside within the operating system itself or may be offered by another infrastructure providing automated account management capabilities. Automated mechanisms may be composed of differing technologies that, when placed together, contain an overall automated mechanism supporting an organization's automated account management requirements. This is not required to be provided by Red Hat Enterprise Linux 9 and must be implemented via a third party solution. |
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| 419 | CCI-001958,CCI-003959 | SRG-OS-000378-GPOS-00163,SRG-APP-000141-CTR-000315 | CCE-84203-9 | The operating system must authenticate peripherals before establishing a connection. | Red Hat Enterprise Linux 9 must have the USBGuard package installed. | Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include, but are not limited to, such devices as flash drives, external storage, and printers. |
The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. |
Applicable - Configurable | Verify the operating system authenticates peripherals before establishing a connection. If it does not, this is a finding. | Verify USBGuard is installed on the operating system with the following command: $ sudo dnf list installed usbguard Example output: Installed Packages usbguard.x86_64 1.0.0-10.el9_1.2 @rhel-9-for-x86_64-appstream-rpms If the USBGuard package is not installed, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding. |
Install the usbguard package with the following command: $ sudo dnf install usbguard |
CAT II | |||||
| 420 | CCI-001958,CCI-003959 | SRG-OS-000378-GPOS-00163,SRG-APP-000141-CTR-000315 | CCE-84205-4 | The operating system must authenticate peripherals before establishing a connection. | Red Hat Enterprise Linux 9 must have the USBGuard package enabled. | Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include, but are not limited to, such devices as flash drives, external storage, and printers. |
The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. |
Applicable - Configurable | Verify the operating system authenticates peripherals before establishing a connection. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 has USBGuard enabled with the following command: $ systemctl is-active usbguard active If usbguard is not active, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding. |
To enable the USBGuard service run the following command: $ sudo systemctl enable --now usbguard |
CAT II | |||||
| 421 | CCI-001958 | SRG-OS-000378-GPOS-00163 | CCE-88882-6 | The operating system must authenticate peripherals before establishing a connection. | Red Hat Enterprise Linux 9 must block unauthorized peripherals before establishing a connection. | Without authenticating devices, unidentified or unknown devices may be introduced, thereby facilitating malicious activity. Peripherals include, but are not limited to, such devices as flash drives, external storage, and printers. |
The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. |
Applicable - Configurable | Verify the operating system authenticates peripherals before establishing a connection. If it does not, this is a finding. | Verify the USBGuard has a policy configured with the following command: $ usbguard list-rules allow id 1d6b:0001 serial If the command does not return results or an error is returned, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding. If the system is virtual machine with no virtual or physical USB peripherals attached, this is not a finding. |
Configure the operating system to enable the blocking of unauthorized peripherals with the following command: Note: This command must be run from a root shell and will create an allow list for any usb devices currently connect to the system. # usbguard generate-policy --no-hash > /etc/usbguard/rules.conf Note: Enabling and starting usbguard without properly configuring it for an individual system will immediately prevent any access over a usb device such as a keyboard or mouse. |
CAT II | |||||
| 422 | CCI-000139 | SRG-OS-000046-GPOS-00022 | CCE-90826-9 | The operating system must alert the ISSO and SA (at a minimum) in the event of an audit processing failure. | Red Hat Enterprise Linux 9 must have mail aliases to notify the information system security officer (ISSO) and system administrator (SA) (at a minimum) in the event of an audit processing failure. | It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
Applicable - Configurable | Verify the operating system alerts the ISSO and SA (at a minimum) in the event of an audit processing failure. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to notify the appropriate interactive users in the event of an audit processing failure. Find the alias maps that are being used with the following command: $ postconf alias_maps alias_maps = hash:/etc/aliases Query the Postfix alias maps for an alias for the root user with the following command: $ postmap -q root hash:/etc/aliases isso If an alias is not set, this is a finding. |
Edit the aliases map file (by default /etc/aliases) used by Postfix and configure a root alias (using the user ISSO as an example): root: ISSO and then update the aliases database with the command: $ sudo newaliases |
CAT II | |||||
| 423 | CCI-000139 | SRG-OS-000046-GPOS-00022 | CCE-89064-0 | The operating system must alert the ISSO and SA (at a minimum) in the event of an audit processing failure. | Red Hat Enterprise Linux 9 must forward mail from postmaster to the root account using a postfix alias. | It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. |
Applicable - Configurable | Verify the operating system alerts the ISSO and SA (at a minimum) in the event of an audit processing failure. If it does not, this is a finding. | Verify that the administrators are notified in the event of an audit processing failure. Check that the "/etc/aliases" file has a defined value for "root". $ sudo grep "postmaster:\s*root$" /etc/aliases If the command does not return a line, or the line is commented out, ask the system administrator to indicate how they and the information systems security officer (ISSO) are notified of an audit process failure. If there is no evidence of the proper personnel being notified of an audit processing failure, this is a finding. |
Configure a valid email address as an alias for the root account. Append the following line to "/etc/aliases": postmaster: root Then, run the following command: $ sudo newaliases |
CAT II | |||||
| 424 | CCI-000140,CCI-000139 | SRG-OS-000046-GPOS-00022,SRG-OS-000047-GPOS-00023 | CCE-83709-6 | The operating system must alert the ISSO and SA (at a minimum) in the event of an audit processing failure. | Red Hat Enterprise Linux 9 must take appropriate action when a critical audit processing failure occurs. | It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. |
Applicable - Configurable | Verify the operating system alerts the ISSO and SA (at a minimum) in the event of an audit processing failure. If it does not, this is a finding. | Verify the audit service is configured to panic on a critical error with the following command: $ sudo grep "\-f" /etc/audit/audit.rules -f 2 If the value for "-f" is not "2", and availability is not documented as an overriding concern, this is a finding. |
Configure Red Hat Enterprise Linux 9 to shut down when auditing failures occur. Add the following line to the bottom of the /etc/audit/audit.rules file: -f 2 |
CAT II | |||||
| 425 | CCI-001855,CCI-000139 | SRG-OS-000046-GPOS-00022,SRG-OS-000343-GPOS-00134 | CCE-83698-1 | The operating system must alert the ISSO and SA (at a minimum) in the event of an audit processing failure. | The Red Hat Enterprise Linux 9 System Administrator (SA) and/or Information System Security Officer (ISSO) (at a minimum) must be alerted of an audit processing failure event. | It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. |
Applicable - Configurable | Verify the operating system alerts the ISSO and SA (at a minimum) in the event of an audit processing failure. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to notify the SA and/or ISSO (at a minimum) in the event of an audit processing failure with the following command: $ sudo grep action_mail_acct /etc/audit/auditd.conf action_mail_acct = root If the value of the "action_mail_acct" keyword is not set to "root" and/or other accounts for security personnel, the "action_mail_acct" keyword is missing, or the retuned line is commented out, ask the system administrator to indicate how they and the ISSO are notified of an audit process failure. If there is no evidence of the proper personnel being notified of an audit processing failure, this is a finding. |
Configure "auditd" service to notify the SA and ISSO in the event of an audit processing failure. Edit the following line in "/etc/audit/auditd.conf" to ensure that administrators are notified via email for those situations: action_mail_acct = root The audit daemon must be restarted for changes to take effect. |
CAT II | |||||
| 426 | CCI-004066 | SRG-OS-000075-GPOS-00043 | CCE-83610-6 | Operating systems must enforce 24 hours/1 day as the minimum password lifetime. | Red Hat Enterprise Linux 9 passwords for new users or password changes must have a 24 hours minimum password lifetime restriction in /etc/login.defs. | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement. |
Applicable - Configurable | Verify operating system enforces 24 hours/1 day as the minimum password lifetime. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 enforces 24 hours as the minimum password lifetime for new user accounts. Check for the value of "PASS_MIN_DAYS" in "/etc/login.defs" with the following command: $ grep -i pass_min_days /etc/login.defs PASS_MIN_DAYS 1 If the "PASS_MIN_DAYS" parameter value is not "1" or greater, or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce 24 hours as the minimum password lifetime. Add the following line in "/etc/login.defs" (or modify the line to have the required value): PASS_MIN_DAYS 1 |
CAT II | |||||
| 427 | CCI-004066 | SRG-OS-000075-GPOS-00043 | CCE-89069-9 | Operating systems must enforce 24 hours/1 day as the minimum password lifetime. | Red Hat Enterprise Linux 9 passwords must have a 24 hours/1 day minimum password lifetime restriction in /etc/shadow. | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. |
Applicable - Configurable | Verify operating system enforces 24 hours/1 day as the minimum password lifetime. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has configured the minimum time period between password changes for each user account is one day or greater with the following command: $ sudo awk -F: '$4 < 1 {print $1 " " $4}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding. |
Configure non-compliant accounts to enforce a 24 hours/1 day minimum password lifetime: $ sudo passwd -n 1 [user] |
CAT II | |||||
| 428 | CCI-000366 | SRG-OS-000480-GPOS-00228,SRG-OS-000480-GPOS-00227 | CCE-87721-7 | The operating system must define default permissions for all authenticated users in such a way that the user can only read and modify their own files. | Red Hat Enterprise Linux 9 must define default permissions for the c shell. | Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. | The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. | Applicable - Configurable | Verify the operating system defines default permissions for all authenticated users in such a way that the user can only read and modify their own files. If it does not, this is a finding. | Verify the "umask" setting is configured correctly in the "/etc/csh.cshrc" file with the following command: Note: If the value of the "umask" parameter is set to "000" "/etc/csh.cshrc" file, the Severity is raised to a CAT I. $ grep umask /etc/csh.cshrc umask 077 umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to define default permissions for all authenticated users using the c shell. Add or edit the lines for the "umask" parameter in the "/etc/csh.cshrc" file to "077": umask 077 |
CAT II | |||||
| 429 | CCI-000366 | SRG-OS-000480-GPOS-00228 | CCE-83647-8 | The operating system must define default permissions for all authenticated users in such a way that the user can only read and modify their own files. | Red Hat Enterprise Linux 9 must define default permissions for all authenticated users in such a way that the user can only read and modify their own files. | Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. | Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access. | Applicable - Configurable | Verify the operating system defines default permissions for all authenticated users in such a way that the user can only read and modify their own files. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 defines default permissions for all authenticated users in such a way that the user can only read and modify their own files with the following command: Note: If the value of the "UMASK" parameter is set to "000" in "/etc/login.defs" file, the Severity is raised to a CAT I. # grep -i umask /etc/login.defs UMASK 077 If the value for the "UMASK" parameter is not "077", or the "UMASK" parameter is missing or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the lines for the "UMASK" parameter in the "/etc/login.defs" file to "077": UMASK 077 |
CAT II | |||||
| 430 | CCI-000366 | SRG-OS-000480-GPOS-00228,SRG-OS-000480-GPOS-00227 | CCE-90828-5 | The operating system must define default permissions for all authenticated users in such a way that the user can only read and modify their own files. | Red Hat Enterprise Linux 9 must define default permissions for the system default profile. | Setting the most restrictive default permissions ensures that when new accounts are created they do not have unnecessary access. | The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. | Applicable - Configurable | Verify the operating system defines default permissions for all authenticated users in such a way that the user can only read and modify their own files. If it does not, this is a finding. | Verify the "umask" setting is configured correctly in the "/etc/profile" file with the following command: Note: If the value of the "umask" parameter is set to "000" "/etc/profile" file, the Severity is raised to a CAT I. $ grep umask /etc/profile umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the lines for the "umask" parameter in the "/etc/profile" file to "077": umask 077 |
CAT II | |||||
| 431 | CCI-002363 | SRG-OS-000280-GPOS-00110 | The operating system must provide a logoff capability for user-initiated communications sessions when requiring user access authentication. | Red Hat Enterprise Linux 9 must provide a logoff capability for user-initiated communications sessions when requiring user access authentication. | If a user cannot explicitly end an operating system session, the session may remain open and be exploited by an attacker; this is referred to as a zombie session. Information resources to which users gain access via authentication include, for example, local workstations and remote services. For some types of interactive sessions, including, for example, remote logon, information systems typically send logoff messages as final messages prior to terminating sessions. |
If a user cannot explicitly end an operating system session, the session may remain open and be exploited by an attacker; this is referred to as a zombie session. Information resources to which users gain access via authentication includes for example, local workstations and remote services. For some types of interactive sessions, including, for example, remote logon, information systems typically send logoff messages as final messages prior to terminating sessions. |
Applicable - Inherently Met | Verify the operating system provides a logoff capability for user-initiated communications sessions when requiring user access authentication. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | The "logoff" and "exit" commands are baked into the OS and are available to all users and the user can terminate a remote session by closing their SSH terminal. | The use of the "exit" command will end any communication session on the system. This is part of the kernel and cannot be removed without recompiling. |
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| 432 | CCI-001443,CCI-001444,CCI-002421,CCI-002418 | SRG-OS-000299-GPOS-00117,SRG-OS-000300-GPOS-00118,SRG-OS-000424-GPOS-00188,SRG-OS-000481-GPOS-000481 | CCE-84066-0 | The operating system must implement cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by alternative physical safeguards, such as, at a minimum, a Protected Distribution System (PDS). | Red Hat Enterprise Linux 9 wireless network adapters must be disabled. | Encrypting information for transmission protects information from unauthorized disclosure and modification. Cryptographic mechanisms implemented to protect information integrity include, for example, cryptographic hash functions which have common application in digital signatures, checksums, and message authentication codes. Use of this requirement will be limited to situations where the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process. When transmitting data, operating systems need to leverage transmission protection mechanisms such as TLS, SSL VPNs, or IPSec. Alternative physical protection measures include PDS. PDSs are used to transmit unencrypted classified National Security Information (NSI) through an area of lesser classification or control. Since the classified NSI is unencrypted, the PDS must provide adequate electrical, electromagnetic, and physical safeguards to deter exploitation. |
This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with Red Hat Enterprise Linux 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DOD requirements for wireless data transmission and be approved for use by the Authorizing Official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the Red Hat Enterprise Linux 9 operating system. | Applicable - Configurable | Verify the operating system implements cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by alternative physical safeguards, such as, at a minimum, a Protected Distribution System (PDS). If it does not, this is a finding. |
Verify there are no wireless interfaces configured on the system with the following command: Note: This requirement is Not Applicable for systems that do not have physical wireless network radios. $ nmcli device status DEVICE TYPE STATE CONNECTION virbr0 bridge connected virbr0 wlp7s0 wifi connected wifiSSID enp6s0 ethernet disconnected -- p2p-dev-wlp7s0 wifi-p2p disconnected -- lo loopback unmanaged -- virbr0-nic tun unmanaged -- If a wireless interface is configured and has not been documented and approved by the information system security officer (ISSO), this is a finding. |
Configure the system to disable all wireless network interfaces with the following command: $ nmcli radio all off |
CAT I | |||||
| 433 | CCI-000068 | SRG-OS-000423-GPOS-00187,SRG-OS-000033-GPOS-00014,SRG-OS-000424-GPOS-00188 | CCE-87522-9 | The operating system must implement cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by alternative physical safeguards, such as, at a minimum, a Protected Distribution System (PDS). | Red Hat Enterprise Linux 9 must force a frequent session key renegotiation for SSH connections to the server. | Encrypting information for transmission protects information from unauthorized disclosure and modification. Cryptographic mechanisms implemented to protect information integrity include, for example, cryptographic hash functions which have common application in digital signatures, checksums, and message authentication codes. Use of this requirement will be limited to situations where the data owner has a strict requirement for ensuring data integrity and confidentiality is maintained at every step of the data transfer and handling process. When transmitting data, operating systems need to leverage transmission protection mechanisms such as TLS, SSL VPNs, or IPSec. Alternative physical protection measures include PDS. PDSs are used to transmit unencrypted classified National Security Information (NSI) through an area of lesser classification or control. Since the classified NSI is unencrypted, the PDS must provide adequate electrical, electromagnetic, and physical safeguards to deter exploitation. |
Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Session key regeneration limits the chances of a session key becoming compromised. |
Applicable - Configurable | Verify the operating system implements cryptographic mechanisms to prevent unauthorized disclosure of information and/or detect changes to information during transmission unless otherwise protected by alternative physical safeguards, such as, at a minimum, a Protected Distribution System (PDS). If it does not, this is a finding. |
Verify the SSH server is configured to force frequent session key renegotiation with the following command: $ sudo grep -i rekeyLimit /etc/ssh/sshd_config RekeyLimit 1G 1h If "RekeyLimit" does not have a maximum data amount and maximum time defined, is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to force a frequent session key renegotiation for SSH connections to the server by adding or modifying the following line in the "/etc/ssh/sshd_config" file: RekeyLimit 1G 1h Restart the SSH daemon for the settings to take effect. $ sudo systemctl restart sshd.service |
CAT I | |||||
| 434 | CCI-000044 | SRG-OS-000021-GPOS-00005 | CCE-86100-5 | The operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. | Red Hat Enterprise Linux 9 must log username information when unsuccessful logon attempts occur. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | Without auditing of these events, it may be harder or impossible to identify what an attacker did after an attack. | Applicable - Configurable | Verify that the operating system enforces the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. If it does not, this is a finding. | Verify the "/etc/security/faillock.conf" file is configured to log username information when unsuccessful logon attempts occur with the following command: $ grep audit /etc/security/faillock.conf audit If the "audit" option is not set, is missing, or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to log username information when unsuccessful logon attempts occur. Add/modify the "/etc/security/faillock.conf" file to match the following line: audit |
CAT II | |||||
| 435 | CCI-000044 | SRG-OS-000021-GPOS-00005,SRG-OS-000329-GPOS-00128 | CCE-86068-4 | The operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. | Red Hat Enterprise Linux 9 must ensure account lockouts persist. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | Having lockouts persist across reboots ensures that account is only unlocked by an administrator. If the lockouts did not persist across reboots, an attacker could simply reboot the system to continue brute force attacks against the accounts on the system. | Applicable - Configurable | Verify that the operating system enforces the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. If it does not, this is a finding. | Verify the "/etc/security/faillock.conf" file is configured use a nondefault faillock directory to ensure contents persist after reboot with the following command: $ grep 'dir =' /etc/security/faillock.conf dir = /var/log/faillock If the "dir" option is not set to a nondefault documented tally log directory, is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 maintain the contents of the faillock directory after a reboot. Add/modify the "/etc/security/faillock.conf" file to match the following line: dir = /var/log/faillock |
CAT II | |||||
| 436 | CCI-000044 | SRG-OS-000021-GPOS-00005 | CCE-86249-0 | The operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. | Red Hat Enterprise Linux 9 must configure SELinux context type to allow the use of a nondefault faillock tally directory. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | Not having the correct SELinux context on the faillock directory may lead to unauthorized access to the directory. | Applicable - Configurable | Verify that the operating system enforces the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. If it does not, this is a finding. | Verify the location of the nondefault tally directory for the pam_faillock module with the following command: Note: If the system does not have SELinux enabled and enforcing a targeted policy, or if the pam_faillock module is not configured for use, this requirement is Not Applicable. $ grep 'dir =' /etc/security/faillock.conf dir = /var/log/faillock Check the security context type of the nondefault tally directory with the following command: $ ls -Zd /var/log/faillock unconfined_u:object_r:faillog_t:s0 /var/log/faillock If the security context type of the nondefault tally directory is not "faillog_t", this is a finding. |
Configure Red Hat Enterprise Linux 9 to allow the use of a nondefault faillock tally directory while SELinux enforces a targeted policy. Create a nondefault faillock tally directory (if it does not already exist) with the following example: $ sudo mkdir /var/log/faillock Update the /etc/selinux/targeted/contexts/files/file_contexts.local with "faillog_t" context type for the nondefault faillock tally directory with the following command: $ sudo semanage fcontext -a -t faillog_t "/var/log/faillock(/.*)?" Next, update the context type of the nondefault faillock directory/subdirectories and files with the following command: $ sudo restorecon -R -v /var/log/faillock |
CAT II | |||||
| 437 | CCI-000044 | SRG-OS-000021-GPOS-00005 | CCE-86917-2 | The operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. | Red Hat Enterprise Linux 9 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | If the pam_faillock.so module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks. | Applicable - Configurable | Verify that the operating system enforces the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. If it does not, this is a finding. | Verify the pam_faillock.so module is present in the "/etc/pam.d/system-auth" file: $ grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/system-auth" file with the "preauth" line listed before pam_unix.so, this is a finding. |
Configure Red Hat Enterprise Linux 9 to include the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" file to match the following lines: Note: The "preauth" line must be listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so |
CAT II | |||||
| 438 | CCI-000044 | SRG-OS-000021-GPOS-00005 | CCE-86932-1 | The operating system must enforce the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. | Red Hat Enterprise Linux 9 must configure the use of the pam_faillock.so module in the /etc/pam.d/password-auth file. | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. | If the pam_faillock.so module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks. | Applicable - Configurable | Verify that the operating system enforces the limit of three consecutive invalid logon attempts by a user during a 15-minute time period. If it does not, this is a finding. | Verify the pam_faillock.so module is present in the "/etc/pam.d/password-auth" file: $ grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the pam_faillock.so module is not present in the "/etc/pam.d/password-auth" file with the "preauth" line listed before pam_unix.so, this is a finding. |
Configure Red Hat Enterprise Linux 9 to include the use of the pam_faillock.so module in the /etc/pam.d/password-auth file. Add/modify the appropriate sections of the "/etc/pam.d/password-auth" file to match the following lines: Note: The "preauth" line must be listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so |
CAT II | |||||
| 439 | CCI-001082 | SRG-OS-000132-GPOS-00067 | The operating system must separate user functionality (including user interface services) from operating system management functionality. | Red Hat Enterprise Linux 9 must separate user functionality (including user interface services) from operating system management functionality. | Operating system management functionality includes functions necessary for administration and requires privileged user access. Allowing non-privileged users to access operating system management functionality capabilities increases the risk that non-privileged users may obtain elevated privileges. Operating system management functionality includes functions necessary to administer console, network components, workstations, or servers and typically requires privileged user access. The separation of user functionality from information system management functionality is either physical or logical and is accomplished by using different computers, different central processing units, different instances of the operating system, different network addresses, different TCP/UDP ports, virtualization techniques, combinations of these methods, or other methods, as appropriate. An example of this type of separation is observed in web administrative interfaces that use separate authentication methods for users of any other information system resources. This may include isolating the administrative interface on a different security domain and with additional access controls. |
Operating system management functionality includes functions necessary for administration and requires privileged user access. Allowing non-privileged users to access operating system management functionality capabilities increases the risk that non-privileged users may obtain elevated privileges. Operating system management functionality includes functions necessary to administer console, network components, workstations, or servers and typically requires privileged user access. The separation of user functionality from information system management functionality is either physical or logical and is accomplished by using different computers, different central processing units, different instances of the operating system, different network addresses, different TCP/UDP ports, virtualization techniques, combinations of these methods, or other methods, as appropriate. An example of this type of separation is observed in web administrative interfaces that use separate authentication methods for users of any other information system resources. This may include isolating the administrative interface on a different security domain and with additional access controls. |
Applicable - Inherently Met | Verify the operating system separates user functionality (including user interface services) from operating system management functionality. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | Red Hat Enterprise Linux 9 management functionality must be executed by the administrator user, which is only accessible through the sudo command (with a proper authentication request). The sudo manpage has more information. | The UNIX permissions construct separates user and privileged user (the Red Hat Enterprise Linux 9 operating system accounts) access. | ||||
| 440 | CCI-000057,CCI-000060 | SRG-OS-000029-GPOS-00010,SRG-OS-000031-GPOS-00012 | CCE-89876-7 | The operating system must conceal, via the session lock, information previously visible on the display with a publicly viewable image. | Red Hat Enterprise Linux 9 must automatically lock command line user sessions after 15 minutes of inactivity. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, tmux can be configured to identify when a user's session has idled and take action to initiate a session lock. | Applicable - Configurable | Verify the operating system conceals, via the session lock, information previously visible on the display with a publicly viewable image. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 initiates a session lock after 15 minutes of inactivity. Check the value of the system inactivity timeout with the following command: $ grep -i lock-after-time /etc/tmux.conf set -g lock-after-time 900 If "lock-after-time" is not set to "900" or less in the global tmux configuration file to enforce session lock after inactivity, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce session lock after a period of 15 minutes of inactivity by adding the following line to the "/etc/tmux.conf" global configuration file: set -g lock-after-time 900 |
CAT II | |||||
| 441 | CCI-000060 | SRG-OS-000031-GPOS-00012 | CCE-88733-1 | The operating system must conceal, via the session lock, information previously visible on the display with a publicly viewable image. | Red Hat Enterprise Linux 9 must conceal, via the session lock, information previously visible on the display with a publicly viewable image. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. The operating system session lock event must include an obfuscation of the display screen so as to prevent other users from reading what was previously displayed. Publicly viewable images can include static or dynamic images, for example, patterns used with screen savers, photographic images, solid colors, a clock, a battery life indicator, or a blank screen, with the additional caveat that none of the images convey sensitive information. |
Setting the screensaver mode to blank-only conceals the contents of the display from passersby. | Applicable - Configurable | Verify the operating system conceals, via the session lock, information previously visible on the display with a publicly viewable image. If it does not, this is a finding. | To ensure the screensaver is configured to be blank, run the following command: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ gsettings get org.gnome.desktop.screensaver picture-uri If properly configured, the output should be "''". To ensure that users cannot set the screensaver background, run the following: $ grep picture-uri /etc/dconf/db/local.d/locks/* If properly configured, the output should be "/org/gnome/desktop/screensaver/picture-uri". If it is not set or configured properly, this is a finding. |
The dconf settings can be edited in the /etc/dconf/db/* location. First, add or update the [org/gnome/desktop/screensaver] section of the "/etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/desktop/screensaver] picture-uri='' Then, add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/screensaver/picture-uri Finally, update the dconf system databases: $ sudo dconf update |
CAT II | |||||
| 442 | CCI-002364 | SRG-OS-000281-GPOS-00111 | The operating system must display an explicit logoff message to users indicating the reliable termination of authenticated communications sessions. | Red Hat Enterprise Linux 9 must display an explicit logoff message to users indicating the reliable termination of authenticated communications sessions. | If a user cannot explicitly end an operating system session, the session may remain open and be exploited by an attacker; this is referred to as a zombie session. Users need to be aware of whether or not the session has been terminated. Information resources to which users gain access via authentication include, for example, local workstations and remote services. Logoff messages can be displayed after authenticated sessions have been terminated. However, for some types of interactive sessions, including, for example, remote logon, information systems typically send logoff messages as final messages prior to terminating sessions. |
If a user cannot explicitly end an operating system session, the session may remain open and be exploited by an attacker; this is referred to as a zombie session. Users need to be aware of whether or not the session has been terminated. Information resources to which users gain access via authentication includes for example, local workstations and remote services. Logoff messages can be displayed after authenticated sessions have been terminated. However, for some types of interactive sessions, including, for example, remote logon, and information systems typically send logoff messages as final messages prior to terminating sessions. |
Applicable - Inherently Met | Verify the operating system displays an explicit logoff message to users indicating the reliable termination of authenticated communications sessions. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. | Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | When logging off from a SSH terminal session, SSH prints "Connection to <host> closed". This is hard coded in client_loop() in clientloop.c, https://github.com/openssh/openssh-portable/blob/master/clientloop.c When the remote ends the connection, a message is also printed. "Connection to <host> closed by remote host". This message is hard-code in client_process_net_input() in clientloop.c | Red Hat Enterprise Linux 9 meets this requirement and it is not configurable. | ||||
| 443 | CCI-002696 | SRG-OS-000445-GPOS-00199,SRG-APP-000233-CTR-000585 | CCE-84074-4 | The operating system must verify correct operation of all security functions. | Red Hat Enterprise Linux 9 must enable the SELinux targeted policy. | Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. |
Setting the SELinux policy to "targeted" or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services. Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in "permissive" mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to "targeted". |
Applicable - Configurable | Verify the operating system verifies correct operation of all security functions. If it does not, this is a finding. | Verify the SELINUX on Red Hat Enterprise Linux 9 is using the targeted policy with the following command: $ sestatus | grep policy Loaded policy name: targeted If the loaded policy name is not "targeted", this is a finding. |
Configure Red Hat Enterprise Linux 9 to use the targetd SELINUX policy. Edit the file "/etc/selinux/config" and add or modify the following line: SELINUXTYPE=targeted A reboot is required for the changes to take effect. |
CAT II | |||||
| 444 | CCI-002696,CCI-001084 | SRG-OS-000445-GPOS-00199,SRG-OS-000134-GPOS-00068 | CCE-84079-3 | The operating system must verify correct operation of all security functions. | Red Hat Enterprise Linux 9 must use a Linux Security Module configured to enforce limits on system services. | Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. |
Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. |
Applicable - Configurable | Verify the operating system verifies correct operation of all security functions. If it does not, this is a finding. | Ensure that Red Hat Enterprise Linux 9 verifies correct operation of security functions through the use of SELinux with the following command: $ getenforce Enforcing If SELINUX is not set to "Enforcing", this is a finding. Verify that SELinux is configured to be enforcing at boot. grep "SELINUX=" /etc/selinux/config # SELINUX= can take one of these three values: # NOTE: In earlier Fedora kernel builds, SELINUX=disabled would also SELINUX=enforcing If SELINUX line is missing, commented out, or not set to "enforcing", this is a finding. |
Configure Red Hat Enterprise Linux 9 to verify correct operation of security functions. Edit the file "/etc/selinux/config" and add or modify the following line: SELINUX=enforcing A reboot is required for the changes to take effect. |
CAT II | |||||
| 445 | CCI-000366 | SRG-OS-000480-GPOS-00225,SRG-OS-000072-GPOS-00040 | CCE-88413-0 | The operating system must prevent the use of dictionary words for passwords. | Red Hat Enterprise Linux 9 Must Prevent The Use Of Dictionary Words For Passwords. | If the operating system allows the user to select passwords based on dictionary words, then this increases the chances of password compromise by increasing the opportunity for successful guesses and brute-force attacks. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If Red Hat Enterprise Linux 9 allows the user to select passwords based on dictionary words, this increases the chances of password compromise by increasing the opportunity for successful guesses, and brute-force attacks. |
Applicable - Configurable | Verify the operating system prevents the use of dictionary words for passwords. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents the use of dictionary words for passwords with the following command: $ sudo grep dictcheck /etc/security/pwquality.conf /etc/pwquality.conf.d/*.conf /etc/security/pwquality.conf:dictcheck=1 If "dictcheck" does not have a value other than "0", or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent the use of dictionary words for passwords. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the /etc/pwquality.conf.d/ directory to contain the "dictcheck" parameter: dictcheck=1 |
CAT II | |||||
| 446 | CCI-003980 | SRG-OS-000362-GPOS-00149 | The operating system must prohibit user installation of system software without explicit privileged status. | Red Hat Enterprise Linux 9 must prohibit user installation of system software without explicit privileged status. | Allowing regular users to install software, without explicit privileges, creates the risk that untested or potentially malicious software will be installed on the system. Explicit privileges (escalated or administrative privileges) provide the regular user with explicit capabilities and control that exceeds the rights of a regular user. Operating system functionality will vary, and while users are not permitted to install unapproved software, there may be instances where the organization allows the user to install approved software packages, such as from an approved software repository. The operating system or software configuration management utility must enforce control of software installation by users based upon what types of software installations are permitted (e.g., updates and security patches to existing software) and what types of installations are prohibited (e.g., software whose pedigree with regard to being potentially malicious is unknown or suspect) by the organization. |
Allowing regular users to install software, without explicit privileges, creates the risk that untested or potentially malicious software will be installed on the system. Explicit privileges (escalated or administrative privileges) provide the regular user with explicit capabilities and control that exceeds the rights of a regular user. Operating system functionality will vary, and while users are not permitted to install unapproved software, there may be instances where the organization allows the user to install approved software packages, such as from an approved software repository. The operating system or software configuration management utility must enforce control of software installation by users based upon what types of software installations are permitted (e.g., updates and security patches to existing software) and what types of installations are prohibited (e.g., software whose pedigree with regard to being potentially malicious is unknown or suspect) by the organization. |
Applicable - Inherently Met | Verify the operating system prohibits user installation of system software without explicit privileged status. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. | Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. | CAT II | Red Hat Enterprise Linux 9 uses DNF or Dandified YUM, the next generation version of the Yellowdog Updater, Modified and RPM (Red Hat Package Manager) to install system software. Both of these utilities and the archive repositories are installed with root privileges and they require root privileges to execute. | The UNIX permissions construct separates user and privileged user (the operating system accounts) access. | ||||
| 447 | CCI-003959 | SRG-OS-000690-GPOS-00140 | The operating system must prohibit the use or connection of unauthorized hardware components. | Red Hat Enterprise Linux 9 must prohibit the use or connection of unauthorized hardware components. | Hardware components provide the foundation for organizational systems and the platform for the execution of authorized software programs. Managing the inventory of hardware components and controlling which hardware components are permitted to be installed or connected to organizational systems is essential to provide adequate security. | pending | Verify the operating system is configured to prohibit the use or connection of unauthorized hardware components. If the operating system is not configured to prohibit the use or connection of unauthorized hardware components, this is a finding. |
CAT II | |||||||||
| 448 | CCI-002824,CCI-001084 | SRG-OS-000433-GPOS-00192,SRG-OS-000134-GPOS-00068 | CCE-83986-0 | The operating system must isolate security functions from nonsecurity functions. | Red Hat Enterprise Linux 9 must clear SLUB/SLAB objects to prevent use-after-free attacks. | An isolation boundary provides access control and protects the integrity of the hardware, software, and firmware that perform security functions. Security functions are the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Operating systems implement code separation (i.e., separation of security functions from nonsecurity functions) in a number of ways, including through the provision of security kernels via processor rings or processor modes. For non-kernel code, security function isolation is often achieved through file system protections that serve to protect the code on disk and address space protections that protect executing code. Developers and implementers can increase the assurance in security functions by employing well-defined security policy models; structured, disciplined, and rigorous hardware and software development techniques; and sound system/security engineering principles. Implementation may include isolation of memory space and libraries. Operating systems restrict access to security functions through the use of access control mechanisms and by implementing least privilege capabilities. |
Some adversaries launch attacks with the intent of executing code in nonexecutable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can be either hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory. SLAB objects are blocks of physically contiguous memory. SLUB is the unqueued SLAB allocator. |
Applicable - Configurable | Verify the operating system isolates security functions from nonsecurity functions. If it does not, this is a finding. | Verify that GRUB 2 is configured to enable poisoning of SLUB/SLAB objects to mitigate use-after-free vulnerabilities with the following commands: Check that the current GRUB 2 configuration has poisoning of SLUB/SLAB objects enabled: $ sudo grubby --info=ALL | grep args | grep -v 'slub_debug=P' If any output is returned, this is a finding. Check that poisoning of SLUB/SLAB objects is enabled by default to persist in kernel updates: $ sudo grep slub_debug /etc/default/grub GRUB_CMDLINE_LINUX="slub_debug=P" If "slub_debug" does not contain "P", is missing, or is commented out, this is a finding. |
Configure RHEL to enable poisoning of SLUB/SLAB objects with the following commands: $ sudo grubby --update-kernel=ALL --args="slub_debug=P" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="slub_debug=P" |
CAT II | |||||
| 449 | CCI-004066 | SRG-OS-000076-GPOS-00044 | CCE-83606-4 | Operating systems must enforce a 60-day maximum password lifetime restriction. | Red Hat Enterprise Linux 9 user account passwords for new users or password changes must have a 60-day maximum password lifetime restriction in /etc/login.defs. | Any password, no matter how complex, can eventually be cracked; therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. | Any password, no matter how complex, can eventually be cracked; therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. Setting the password maximum age ensures users are required to periodically change their passwords. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise. |
Applicable - Configurable | Verify operating system enforces a 60-day maximum password lifetime restriction. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces a 60-day maximum password lifetime for new user accounts by running the following command: $ grep -i pass_max_days /etc/login.defs PASS_MAX_DAYS 60 If the "PASS_MAX_DAYS" parameter value is greater than "60", or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce a 60-day maximum password lifetime. Add or modify the following line in the "/etc/login.defs" file: PASS_MAX_DAYS 60 |
CAT II | |||||
| 450 | CCI-004066 | SRG-OS-000076-GPOS-00044 | CCE-86031-2 | Operating systems must enforce a 60-day maximum password lifetime restriction. | Red Hat Enterprise Linux 9 user account passwords must have a 60-day maximum password lifetime restriction. | Any password, no matter how complex, can eventually be cracked; therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. | Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. |
Applicable - Configurable | Verify operating system enforces a 60-day maximum password lifetime restriction. If it does not, this is a finding. | Check whether the maximum time period for existing passwords is restricted to 60 days with the following commands: $ sudo awk -F: '$5 > 60 {print $1 "" "" $5}' /etc/shadow $ sudo awk -F: '$5 <= 0 {print $1 "" "" $5}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding. |
Configure non-compliant accounts to enforce a 60-day maximum password lifetime restriction. passwd -x 60 [user] |
CAT II | |||||
| 451 | CCI-004068,CCI-000185 | SRG-OS-000066-GPOS-00034,SRG-OS-000384-GPOS-00167 | CCE-86321-7 | The operating system, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. | Red Hat Enterprise Linux 9, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. | Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. |
Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a certification authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. |
Applicable - Configurable | Verify the operating system, for PKI-based authentication, validates certificates by constructing a certification path (which includes status information) to an accepted trust anchor. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 for PKI-based authentication has valid certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Check that the system has a valid DOD root CA installed with the following command: $ sudo openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem Example output: Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha256WithRSAEncryption Issuer: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Validity Not Before: Mar 20 18:46:41 2012 GMT Not After: Dec 30 18:46:41 2029 GMT Subject: C = US, O = U.S. Government, OU = DoD, OU = PKI, CN = DoD Root CA 3 Subject Public Key Info: Public Key Algorithm: rsaEncryption If the root CA file is not a DOD-issued certificate with a valid date and installed in the "/etc/sssd/pki/sssd_auth_ca_db.pem" location, this is a finding. |
Configure Red Hat Enterprise Linux 9, for PKI-based authentication, to validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Obtain a valid copy of the DOD root CA file from the PKI CA certificate bundle from cyber.mil and copy the DoD_PKE_CA_chain.pem into the following file: /etc/sssd/pki/sssd_auth_ca_db.pem |
CAT II | |||||
| 452 | CCI-001312 | SRG-OS-000205-GPOS-00083 | The operating system must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries. | Red Hat Enterprise Linux 9 must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries. | Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers. |
Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers. |
Applicable - Inherently Met | Verify the operating system generates error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | Common Criteria evaluation. | Red Hat Enterprise Linux 9 is secure in the event of a failure. Authentication and authorizations are still necessary to access the system. |
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| 453 | CCI-000056 | SRG-OS-000028-GPOS-00009,SRG-OS-000030-GPOS-00011 | CCE-86149-2 | The operating system must provide the capability for users to directly initiate a session lock for all connection types. | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, operating systems need to provide users with the ability to manually invoke a session lock so users may secure their session should the need arise for them to temporarily vacate the immediate physical vicinity. |
Applicable - Configurable | Verify the operating system provides the capability for users to directly initiate a session lock for all connection types. If it does not, this is a finding. | CAT II | |||||||||
| 454 | CCI-004083 | SRG-OS-000745-GPOS-00210 | The operating system must accept only external credentials that are NIST-compliant. | Red Hat Enterprise Linux 9 must accept only external credentials that are NIST-compliant. | Acceptance of only NIST-compliant external authenticators applies to organizational systems that are accessible to the public (e.g., public-facing websites). External authenticators are issued by nonfederal government entities and are compliant with [SP 800-63B]. Approved external authenticators meet or exceed the minimum federal government-wide technical, security, privacy, and organizational maturity requirements. Meeting or exceeding federal requirements allows federal government relying parties to trust external authenticators in connection with an authentication transaction at a specified authenticator assurance level. | pending | Verify the operating system is configured to accept only external credentials that are NIST-compliant. If the operating system is not configured to accept only external credentials that are NIST-compliant, this is a finding. |
CAT II | |||||||||
| 455 | CCI-001496,CCI-001494,CCI-001495,CCI-001493 | SRG-OS-000278-GPOS-00108 | CCE-87757-1 | The operating system must use cryptographic mechanisms to protect the integrity of audit tools. | Red Hat Enterprise Linux 9 must use cryptographic mechanisms to protect the integrity of audit tools. | Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools with the purpose of providing the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed in order to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files. |
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files. |
Applicable - Configurable | Verify the operating system uses cryptographic mechanisms to protect the integrity of audit tools. If it does not, this is a finding. | Check that AIDE is properly configured to protect the integrity of the audit tools with the following command: $ sudo cat /etc/aide.conf | grep /usr/sbin/au /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If AIDE is not installed, ask the system administrator (SA) how file integrity checks are performed on the system. If any of the audit tools listed above do not have a corresponding line, ask the SA to indicate what cryptographic mechanisms are being used to protect the integrity of the audit tools. If there is no evidence of integrity protection, this is a finding. |
Add or update the following lines to "/etc/aide.conf", to protect the integrity of the audit tools. /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 |
CAT I | |||||
| 456 | CCI-001953,CCI-004046 | SRG-OS-000375-GPOS-00160,SRG-OS-000376-GPOS-00161 | CCE-83595-9 | The operating system must accept Personal Identity Verification (PIV) credentials. | Red Hat Enterprise Linux 9 must have the opensc package installed. | The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. DoD has mandated the use of the CAC to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. |
The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. The DOD has mandated the use of the common access card (CAC) to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. |
Applicable - Configurable | Verify the operating system accepts Personal Identity Verification (PIV) credentials. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the opensc package installed with the following command: $ sudo dnf list --installed opensc Example output: opensc.x86_64 0.22.0-2.el9 If the "opensc" package is not installed, this is a finding. |
The opensc package can be installed with the following command: $ sudo dnf install opensc |
CAT II | |||||
| 457 | CCI-004046 | SRG-OS-000375-GPOS-00160 | CCE-86280-5 | The operating system must implement multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access. | Red Hat Enterprise Linux 9 must have the pcsc-lite package installed. | Using an authentication device, such as a common access card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DOD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). |
The pcsc-lite package must be installed if it is to be available for multifactor authentication using smart cards. | Applicable - Configurable | Verify the operating system implements multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the pcsc-lite package installed with the following command: $ sudo dnf list --installed pcsc-lite Example output: pcsc-lite.x86_64 1.9.4-1.el9 If the "pcsc-lite" package is not installed, this is a finding. |
The pcsc-lite package can be installed with the following command: $ sudo dnf install pcsc-lite |
CAT II | |||||
| 458 | CCI-004046 | SRG-OS-000375-GPOS-00160 | CCE-87907-2 | The operating system must implement multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access. | The pcscd service on Red Hat Enterprise Linux 9 must be active. | Using an authentication device, such as a common access card (CAC) or token that is separate from the information system, ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. Multifactor solutions that require devices separate from information systems gaining access include, for example, hardware tokens providing time-based or challenge-response authenticators and smart cards such as the U.S. Government Personal Identity Verification (PIV) card and the DOD CAC. A privileged account is defined as an information system account with authorizations of a privileged user. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. This requirement only applies to components where this is specific to the function of the device or has the concept of an organizational user (e.g., VPN, proxy capability). This does not apply to authentication for the purpose of configuring the device itself (management). |
The information system ensures that even if the information system is compromised, that compromise will not affect credentials stored on the authentication device. The daemon program for pcsc-lite and the MuscleCard framework is pcscd. It is a resource manager that coordinates communications with smart card readers and smart cards and cryptographic tokens that are connected to the system. |
Applicable - Configurable | Verify the operating system implements multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access. If it does not, this is a finding. | Verify that the "pcscd" service is active with the following command: $ systemctl is-active pcscd active If the pcscdservice is not active, this is a finding. |
To enable the pcscd service run the following command: $ sudo systemctl enable --now pcscd |
CAT II | |||||
| 459 | CCI-001890,CCI-004926,CCI-004923 | SRG-OS-000355-GPOS-00143,SRG-OS-000356-GPOS-00144,SRG-OS-000359-GPOS-00146 | CCE-87077-4 | The operating system must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Red Hat Enterprise Linux 9 must securely compare internal information system clocks at least every 24 hours with a server synchronized to an authoritative time source, such as the United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). |
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Depending on the infrastructure being used the "pool" directive may not be supported. |
Applicable - Configurable | Verify the operating system, for networked systems, compares internal information system clocks at least every 24 hours with a serve synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is securely comparing internal information system clocks at least every 24 hours with an NTP server with the following commands: $ sudo grep maxpoll /etc/chrony.conf server 0.us.pool.ntp.mil iburst maxpoll 16 If the "maxpoll" option is set to a number greater than 16 or the line is commented out, this is a finding. Verify the "chrony.conf" file is configured to an authoritative DoD time source by running the following command: $ sudo grep -i server /etc/chrony.conf server 0.us.pool.ntp.mil If the parameter "server" is not set or is not set to an authoritative DoD time source, this is a finding. |
Configure Red Hat Enterprise Linux 9 to securely compare internal information system clocks at least every 24 hours with an NTP server by adding/modifying the following line in the /etc/chrony.conf file. server [ntp.server.name] iburst maxpoll 16 |
CAT II | |||||
| 460 | CCI-001890,CCI-004926,CCI-004923 | SRG-OS-000355-GPOS-00143 | CCE-84218-7 | The operating system must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). |
Applicable - Configurable | Verify the operating system, for networked systems, compares internal information system clocks at least every 24 hours with a serve synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). If it does not, this is a finding. | CAT II | |||||||||
| 461 | CCI-004923 | SRG-OS-000355-GPOS-00143 | CCE-84215-3 | The operating system must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Red Hat Enterprise Linux 9 must have the chrony package installed. | Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). |
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. | Applicable - Configurable | Verify the operating system, for networked systems, compares internal information system clocks at least every 24 hours with a serve synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the chrony package installed with the following command: $ sudo dnf list --installed chrony Example output: chrony.x86_64 4.1-3.el9 If the "chrony" package is not installed, this is a finding. |
The chrony package can be installed with the following command: $ sudo dnf install chrony |
CAT II | |||||
| 462 | CCI-004923 | SRG-OS-000355-GPOS-00143 | CCE-84217-9 | The operating system must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). | Red Hat Enterprise Linux 9 chronyd service must be enabled. | Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints). |
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. |
Applicable - Configurable | Verify the operating system, for networked systems, compares internal information system clocks at least every 24 hours with a serve synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). If it does not, this is a finding. | Verify the chronyd service is active with the following command: $ systemctl is-active chronyd active If the chronyd service is not active, this is a finding. |
To enable the chronyd service run the following command: $ sudo systemctl enable --now chronyd |
CAT II | |||||
| 463 | CCI-000213 | SRG-OS-000080-GPOS-00048 | CCE-83594-2 | The operating system must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. | Red Hat Enterprise Linux 9 must require authentication to access single-user mode. | To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. |
To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DOD-approved PKIs, all DOD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. This requirement prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password. |
Applicable - Configurable | Verify the operating system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 requires authentication for single-user mode with the following command: $ grep sulogin /usr/lib/systemd/system/rescue.service ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue If this line is not returned, or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require authentication for single-user mode. Add or modify the following line in the "/usr/lib/systemd/system/rescue.service" file: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue |
CAT II | |||||
| 464 | CCI-000213 | SRG-OS-000080-GPOS-00048 | CCE-87370-3 | The operating system must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. | Red Hat Enterprise Linux 9 must require a unique superusers name upon booting into single-user and maintenance modes. | To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. |
Having a nondefault grub superuser username makes password-guessing attacks less effective. | Applicable - Configurable | Verify the operating system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. If it does not, this is a finding. | Verify the boot loader superuser account has been set with the following command: $ sudo grep -A1 "superusers" /etc/grub2.cfg set superusers="<superusers-account>" export superusers The <superusers-account> is the actual account name different from common names like root, admin, or administrator. If superusers contains easily guessable usernames, this is a finding. |
Configure Red Hat Enterprise Linux 9 to have a unique username for the grub superuser account. Edit the "/etc/grub.d/01_users" file and add or modify the following lines in the "### BEGIN /etc/grub.d/01_users ###" section: set superusers="superusers-account" export superusers Once the superuser account has been added, update the grub.cfg file by running: $ sudo grubby --update-kernel=ALL |
CAT II | |||||
| 465 | CCI-000213 | SRG-OS-000080-GPOS-00048 | CCE-83849-0 | The operating system must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. | Red Hat Enterprise Linux 9 must require a boot loader superuser password. | To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. |
To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DOD-approved PKIs, all DOD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode. |
Applicable - Configurable | Verify the operating system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. If it does not, this is a finding. | Verify the boot loader superuser password has been set and run the following command: $ sudo grep "superusers" /etc/grub2.cfg password_pbkdf2 superusers-account ${GRUB2_PASSWORD} To verify the boot loader superuser account password has been set, and the password encrypted, run the following command: $ sudo cat /boot/grub2/user.cfg GRUB2_PASSWORD=grub.pbkdf2.sha512.10000.C4E08AC72FBFF7E837FD267BFAD7AEB3D42DDC 2C99F2A94DD5E2E75C2DC331B719FE55D9411745F82D1B6CFD9E927D61925F9BBDD1CFAA0080E0 916F7AB46E0D.1302284FCCC52CD73BA3671C6C12C26FF50BA873293B24EE2A96EE3B57963E6D7 0C83964B473EC8F93B07FE749AA6710269E904A9B08A6BBACB00A2D242AD828 If a "GRUB2_PASSWORD" is not set, this is a finding. |
Configure Red Hat Enterprise Linux 9 to require a grub bootloader password for the grub superuser account. Generate an encrypted grub2 password for the grub superuser account with the following command: $ sudo grub2-setpassword Enter password: Confirm password: |
CAT II | |||||
| 466 | CCI-000213 | SRG-OS-000080-GPOS-00048 | CCE-89427-9 | The operating system must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. | Red Hat Enterprise Linux 9 Must Enforce Approved Authorizations For Logical Access To Information And System Resources In Accordance With Applicable Access Control Policies. | To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. |
Having a non-default grub superuser username makes password-guessing attacks less effective. | Applicable - Configurable | Verify the operating system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. If it does not, this is a finding. | To verify the boot loader superuser account has been set, run the following command: sudo grep -A1 "superusers" /etc/grub2-efi.cfg The output should show the following: set superusers=" superusers-account " export superusers where superusers-account is the actual account name different from common names like root, admin, or administrator. If it does not, this is a finding. |
CAT II | ||||||
| 467 | CCI-000213 | SRG-OS-000080-GPOS-00048 | CCE-88654-9 | The operating system must enforce approved authorizations for logical access to information and system resources in accordance with applicable access control policies. | Red Hat Enterprise Linux 9 Must Enforce Approved Authorizations For Logical Access To Information And System Resources In Accordance With Applicable Access Control Policies. | To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DoD-approved PKIs, all DoD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. Access control policies include: identity-based policies, role-based policies, and attribute-based policies. Access enforcement mechanisms include: access control lists, access control matrices, and cryptography. These policies and mechanisms must be employed by the application to control access between users (or processes acting on behalf of users) and objects (e.g., devices, files, records, processes, programs, and domains) in the information system. |
Password protection on the boot loader configuration ensures users with physical access cannot trivially alter important bootloader settings. These include which kernel to use, and whether to enter single-user mode. |
Applicable - Configurable | Verify the operating system enforces approved authorizations for logical access to information and system resources in accordance with applicable access control policies. If it does not, this is a finding. | To verify the boot loader superuser password has been set, run the following command: sudo grep "password" /etc/grub2-efi.cfg The output should show the following: password_pbkdf2 superusers-account ${GRUB2_PASSWORD} To verify the boot loader superuser account password has been set, and the password encrypted, run the following command: sudo cat /boot/grub2/user.cfg The output should be similar to: GRUB2_PASSWORD=grub.pbkdf2.sha512.10000.C4E08AC72FBFF7E837FD267BFAD7AEB3D42DDC 2C99F2A94DD5E2E75C2DC331B719FE55D9411745F82D1B6CFD9E927D61925F9BBDD1CFAA0080E0 916F7AB46E0D.1302284FCCC52CD73BA3671C6C12C26FF50BA873293B24EE2A96EE3B57963E6D7 0C83964B473EC8F93B07FE749AA6710269E904A9B08A6BBACB00A2D242AD828 If it does not, this is a finding. |
CAT II | ||||||
| 468 | CCI-004909 | SRG-OS-000775-GPOS-00230 | The operating system must include only approved trust anchors in trust stores or certificate stores managed by the organization. | Red Hat Enterprise Linux 9 must include only approved trust anchors in trust stores or certificate stores managed by the organization. | Public key infrastructure (PKI) certificates are certificates with visibility external to organizational systems and certificates related to the internal operations of systems, such as application-specific time services. In cryptographic systems with a hierarchical structure, a trust anchor is an authoritative source (i.e., a certificate authority) for which trust is assumed and not derived. A root certificate for a PKI system is an example of a trust anchor. A trust store or certificate store maintains a list of trusted root certificates. | pending | Verify the operating system is configured to include only approved trust anchors in trust stores or certificate stores managed by the organization. If the operating system is not configured to include only approved trust anchors in trust stores or certificate stores managed by the organization, this is a finding. |
CAT II | |||||||||
| 469 | CCI-004066 | SRG-OS-000071-GPOS-00039 | CCE-83566-0 | The operating system must enforce password complexity by requiring that at least one numeric character be used. | Red Hat Enterprise Linux 9 must enforce password complexity by requiring that at least One numeric character be used. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring digits makes password guessing attacks more difficult by ensuring a larger search space. |
Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one numeric character be used. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces password complexity by requiring that at least one numeric character. Check the value for "dcredit" with the following command: $ sudo grep dcredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:dcredit = -1 If the value of "dcredit" is a positive number or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce password complexity by requiring that at least one numeric character be used by setting the "dcredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): dcredit = -1 |
CAT II | |||||
| 470 | CCI-004061 | SRG-OS-000710-GPOS-00160 | The operating system must, for password-based authentication, verify when users create or update passwords the passwords are not found on the list of commonly-used, expected, or compromised passwords in IA-5 (1) (a). | Red Hat Enterprise Linux 9 must, for password-based authentication, verify when users create or update passwords the passwords are not found on the list of commonly-used, expected, or compromised passwords in IA-5 (1) (a). | Password-based authentication applies to passwords regardless of whether they are used in single-factor or multifactor authentication. Long passwords or passphrases are preferable over shorter passwords. Enforced composition rules provide marginal security benefits while decreasing usability. However, organizations may choose to establish certain rules for password generation (e.g., minimum character length for long passwords) under certain circumstances and can enforce this requirement in IA-5(1)(h). Account recovery can occur, for example, in situations when a password is forgotten. Cryptographically protected passwords include salted one-way cryptographic hashes of passwords. The list of commonly used, compromised, or expected passwords includes passwords obtained from previous breach corpuses, dictionary words, and repetitive or sequential characters. The list includes context-specific words, such as the name of the service, username, and derivatives thereof. | pending | Verify the operating system is configured to, for password-based authentication, verify when users create or update passwords the passwords are not found on the list of commonly-used, expected, or compromised passwords in IA-5 (1) (a). If the operating system is not configured to, for password-based authentication, verify when users create or update passwords the passwords are not found on the list of commonly-used, expected, or compromised passwords in IA-5 (1) (a), this is a finding. |
CAT II | |||||||||
| 471 | CCI-001813 | SRG-OS-000364-GPOS-00151 | The operating system must enforce access restrictions. | Red Hat Enterprise Linux 9 must enforce access restrictions. | Failure to provide logical access restrictions associated with changes to system configuration may have significant effects on the overall security of the system. When dealing with access restrictions pertaining to change control, it should be noted that any changes to the hardware, software, and/or firmware components of the operating system can have significant effects on the overall security of the system. Accordingly, only qualified and authorized individuals should be allowed to obtain access to operating system components for the purposes of initiating changes, including upgrades and modifications. Logical access restrictions include, for example, controls that restrict access to workflow automation, media libraries, abstract layers (e.g., changes implemented into third-party interfaces rather than directly into information systems), and change windows (e.g., changes occur only during specified times, making unauthorized changes easy to discover). |
Failure to provide logical access restrictions associated with changes to system configuration may have significant effects on the overall security of the system. When dealing with access restrictions pertaining to change control, it should be noted that any changes to the hardware, software, and/or firmware components of the operating system can have significant effects on the overall security of the system. Accordingly, only qualified and authorized individuals should be allowed to obtain access to operating system components for the purposes of initiating changes, including upgrades and modifications. Logical access restrictions include, for example, controls that restrict access to workflow automation, media libraries, abstract layers (e.g., changes implemented into third-party interfaces rather than directly into information systems), and change windows (e.g., changes occur only during specified times, making unauthorized changes easy to discover). |
Applicable - Inherently Met | Verify the operating system enforces access restrictions. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | The UNIX permissions construct separates user and privileged user (the operating system accounts) access. | Red Hat Enterprise Linux 9 is based on the Linux kernel. The Linux kernel enforces access restrictions as detailed here: https://www.linux.com/tutorials/overview-linux-kernel-security-features/. | ||||
| 472 | CCI-000162,CCI-000163,CCI-000164 | SRG-OS-000057-GPOS-00027,SRG-OS-000058-GPOS-00028,SRG-OS-000059-GPOS-00029 | CCE-83734-4 | The operating system must protect audit information from unauthorized deletion. | Red Hat Enterprise Linux 9 audit log directory must have a mode of 0750 or less permissive to prevent unauthorized read access. | If audit information were to become compromised, then forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve. To ensure the veracity of audit information, the operating system must protect audit information from unauthorized deletion. This requirement can be achieved through multiple methods, which will depend upon system architecture and design. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit information system activity. |
If users can write to audit logs, audit trails can be modified or destroyed. | Applicable - Configurable | Verify the operating system protects audit information from unauthorized deletion. If it does not, this is a finding. | Verify the audit log directories have a correct mode or less permissive mode. Find the location of the audit logs: $ sudo grep "^log_file" /etc/audit/auditd.conf Find the group that owns audit logs: $ sudo grep "^log_group" /etc/audit/auditd.conf Run the following command to check the mode of the system audit logs: $ sudo stat -c "%a %n" [audit_log_directory] Replace "[audit_log_directory]" to the correct audit log directory path, by default this location is "/var/log/audit". If the log_group is "root" or is not set, the correct permissions are 0700, otherwise they are 0750. If audit logs have a more permissive mode, then this is a finding. |
The audit daemon must be restarted for the changes to take effect. | CAT II | |||||
| 473 | CCI-002450,CCI-000068,CCI-002418,CCI-000877 | SRG-OS-000478-GPOS-00223 | CCE-86547-7 | The operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Red Hat Enterprise Linux 9 Must Implement Nist Fips-Validated Cryptography For The Following: To Provision Digital Signatures, To Generate Cryptographic Hashes, And To Protect Unclassified Information Requiring Confidentiality And Cryptographic Protection In Accordance With Applicable Federal Laws, Executive Orders, Directives, Policies, Regulations, And Standards. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. |
Applicable - Configurable | Verify the operating system implements NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. If it does not, this is a finding. | $ sudo dnf list --installed dracut | Configure Red Hat Enterprise Linux 9 to run in FIPS mode. Run the following command to enable FIPS mode: $ sudo fips-mode-setup --enable Check the /etc/dracut.conf.d/40-fips.conf file and make sure it includes the following line: add_dracutmodules+=" fips " The system needs to be rebooted for these changes to take effect. |
CAT I | |||||
| 474 | CCI-000803 | SRG-OS-000120-GPOS-00061 | CCE-83449-9 | The operating system must implement NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. | Red Hat Enterprise Linux 9 must use mechanisms meeting the requirements of applicable federal laws, executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. | Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data. The operating system must implement cryptographic modules adhering to the higher standards approved by the federal government since this provides assurance they have been tested and validated. | Overriding the system crypto policy makes the behavior of Kerberos violate expectations, and makes system configuration more fragmented. | Applicable - Configurable | Verify the operating system implements NIST FIPS-validated cryptography for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards. If it does not, this is a finding. | Verify that the symlink exists and targets the correct Kerberos crypto policy, with the following command: file /etc/crypto-policies/back-ends/krb5.config If command output shows the following line, Kerberos is configured to use the system-wide crypto policy: /etc/crypto-policies/back-ends/krb5.config: symbolic link to /usr/share/crypto-policies/FIPS/krb5.txt If the symlink does not exist or points to a different target, this is a finding. |
Configure Kerberos to use system crypto policy. Create a symlink pointing to system crypto policy in the Kerberos configuration using the following command: $ sudo ln -s /etc/crypto-policies/back-ends/krb5.config /usr/share/crypto-policies/FIPS/krb5.txt |
CAT I | |||||
| 475 | CCI-001851 | SRG-OS-000342-GPOS-00133 | CCE-83648-6 | The operating system must offload audit records onto a different system or media from the system being audited. | Red Hat Enterprise Linux 9 audispd-plugins package must be installed. | Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. |
"audispd-plugins" provides plugins for the real-time interface to the audit subsystem, "audispd". These plugins can do things like relay events to remote machines or analyze events for suspicious behavior. | Applicable - Configurable | Verify the operating system off-loads audit records onto a different system or media from the system being audited. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has the audispd-plugins package for installed with the following command: $ sudo dnf list --installed audispd-plugins Example output: audispd-plugins.x86_64 3.0.7-101.el9_0.2 If the "audispd-plugins" package is not installed, this is a finding. |
The audispd-plugins package can be installed with the following command: $ sudo dnf install audispd-plugins |
CAT III | |||||
| 476 | CCI-002824 | SRG-OS-000433-GPOS-00192,SRG-APP-000450-CTR-001105 | CCE-88577-2 | The operating system must implement non-executable data to protect its memory from unauthorized code execution. | Red Hat Enterprise Linux 9 must implement non-executable data to protect its memory from unauthorized code execution. | Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks. |
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range. This is enabled by default on the latest Red Hat and Fedora systems if supported by the hardware. |
Applicable - Configurable | Verify the operating system implements non-executable data to protect its memory from unauthorized code execution. If it does not, this is a finding. | Verify the NX (no-execution) bit flag is set on the system. Check that the no-execution bit flag is set with the following commands: $ sudo dmesg | grep NX [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection" active, check the cpuinfo settings with the following command: $ sudo grep -i flags /proc/cpuinfo flags : fpu vme de pse tsc ms nx rdtscp lm constant_tsc If "flags" does not contain the "nx" flag, this is a finding. |
Update the GRUB 2 bootloader configuration. Run the following command: $ sudo grubby --update-kernel=ALL --remove-args=noexec |
CAT II | |||||
| 477 | CCI-002824 | SRG-OS-000433-GPOS-00192 | CCE-83970-4 | The operating system must implement non-executable data to protect its memory from unauthorized code execution. | Red Hat Enterprise Linux 9 must implement nonexecutable data to protect its memory from unauthorized code execution. | Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks. |
ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range. This is enabled by default on the latest Red Hat and Fedora systems if supported by the hardware. | Applicable - Configurable | Verify the operating system implements non-executable data to protect its memory from unauthorized code execution. If it does not, this is a finding. | Verify ExecShield is enabled on 64-bit Red Hat Enterprise Linux 9 systems with the following command: $ sudo dmesg | grep '[NX|DX]*protection' [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection" active, this is a finding. |
Update the GRUB 2 bootloader configuration. Run the following command: $ sudo grubby --update-kernel=ALL --remove-args=noexec |
CAT II | |||||
| 478 | CCI-000140 | SRG-OS-000047-GPOS-00023 | CCE-88303-3 | The operating system must shut down by default upon audit failure (unless availability is an overriding concern). | The Red Hat Enterprise Linux 9 audit system must take appropriate action when an error writing to the audit storage volume occurs. | It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server. |
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. | Applicable - Configurable | Verify the operating system shuts down by default upon audit failure (unless availability is an overriding concern). If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 takes the appropriate action when an audit processing failure occurs. Check that Red Hat Enterprise Linux 9 takes the appropriate action when an audit processing failure occurs with the following command: $ sudo grep disk_error_action /etc/audit/auditd.conf disk_error_action = HALT If the value of the "disk_error_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, ask the system administrator to indicate how the system takes appropriate action when an audit process failure occurs. If there is no evidence of appropriate action, this is a finding. |
Configure Red Hat Enterprise Linux 9 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line (depending on configuration "disk_error_action" can be set to "SYSLOG" or "SINGLE" depending on configuration) in "/etc/audit/auditd.conf" file: disk_error_action = HALT If availability has been determined to be more important, and this decision is documented with the ISSO, configure the operating system to notify system administration staff and ISSO staff in the event of an audit processing failure by setting the "disk_error_action" to "SYSLOG". |
CAT II | |||||
| 479 | CCI-000140 | SRG-OS-000047-GPOS-00023 | CCE-88336-3 | The operating system must shut down by default upon audit failure (unless availability is an overriding concern). | The Red Hat Enterprise Linux 9 audit system must take appropriate action when the audit storage volume is full. | It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server. |
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. | Applicable - Configurable | Verify the operating system shuts down by default upon audit failure (unless availability is an overriding concern). If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 takes the appropriate action when the audit storage volume is full. Check that Red Hat Enterprise Linux 9 takes the appropriate action when the audit storage volume is full with the following command: $ sudo grep disk_full_action /etc/audit/auditd.conf disk_full_action = HALT If the value of the "disk_full_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, ask the system administrator to indicate how the system takes appropriate action when an audit storage volume is full. If there is no evidence of appropriate action, this is a finding. |
Configure Red Hat Enterprise Linux 9 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line (depending on configuration "disk_full_action" can be set to "SYSLOG" or "SINGLE" depending on configuration) in "/etc/audit/auditd.conf" file: disk_full_action = HALT If availability has been determined to be more important, and this decision is documented with the ISSO, configure the operating system to notify system administration staff and ISSO staff in the event of an audit processing failure by setting the "disk_full_action" to "SYSLOG". |
CAT II | |||||
| 480 | CCI-000140 | SRG-OS-000047-GPOS-00023,SRG-APP-000098-CTR-000185,SRG-APP-000099-CTR-000190,SRG-APP-000100-CTR-000195,SRG-APP-000100-CTR-000200,SRG-APP-000109-CTR-000215,SRG-APP-000290-CTR-000670,SRG-APP-000357-CTR-000800 | CCE-88396-7 | The operating system must shut down by default upon audit failure (unless availability is an overriding concern). | The Red Hat Enterprise Linux 9 audit system must take appropriate action when the audit files have reached maximum size. | It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. When availability is an overriding concern, other approved actions in response to an audit failure are as follows: 1) If the failure was caused by the lack of audit record storage capacity, the operating system must continue generating audit records if possible (automatically restarting the audit service if necessary), overwriting the oldest audit records in a first-in-first-out manner. 2) If audit records are sent to a centralized collection server and communication with this server is lost or the server fails, the operating system must queue audit records locally until communication is restored or until the audit records are retrieved manually. Upon restoration of the connection to the centralized collection server, action should be taken to synchronize the local audit data with the collection server. |
It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include: software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. | Applicable - Configurable | Verify the operating system shuts down by default upon audit failure (unless availability is an overriding concern). If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 takes the appropriate action when the audit files have reached maximum size with the following command: $ sudo grep max_log_file_action /etc/audit/auditd.conf max_log_file_action = ROTATE If the value of the "max_log_file_action" option is not "ROTATE", "SINGLE", or the line is commented out, ask the system administrator to indicate how the system takes appropriate action when an audit storage volume is full. If there is no evidence of appropriate action, this is a finding. |
Configure Red Hat Enterprise Linux 9 to rotate the audit log when it reaches maximum size. Add or update the following line in "/etc/audit/auditd.conf" file: max_log_file_action = ROTATE |
CAT II | |||||
| 481 | CCI-000206 | SRG-OS-000079-GPOS-00047 | The operating system must obscure feedback of authentication information during the authentication process to protect the information from possible exploitation/use by unauthorized individuals. | Red Hat Enterprise Linux 9 must obscure feedback of authentication information during the authentication process to protect the information from possible exploitation/use by unauthorized individuals. | To prevent the compromise of authentication information, such as passwords during the authentication process, the feedback from the operating system shall not provide any information allowing an unauthorized user to compromise the authentication mechanism. Obfuscation of user-provided information that is typed into the system is a method used when addressing this risk. For example, displaying asterisks when a user types in a password is an example of obscuring feedback of authentication information. |
To prevent the compromise of authentication information, such as passwords during the authentication process, the feedback from Red Hat Enterprise Linux 9 must not provide any information allowing an unauthorized user to compromise the authentication mechanism. Obfuscation of user-provided information that is typed into the system is a method used when addressing this risk. For example, displaying asterisks when a user types in a password is an example of obscuring feedback of authentication information. |
Applicable - Inherently Met | Verify the operating system obscures feedback of authentication information during the authentication process to protect the information from possible exploitation/use by unauthorized individuals. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
The technology inherently meets this requirement. No fix is required. | CAT II | The "passwd", "login", and "sudo" do not display the passwords being typed. The "passwd.c" from the "passwd" source code uses the "getpass" function, which is specific for retrieving passwords, thus does not provide a feedback to the terminal. The "tgetpass.c" from the sudo source code uses "tgetpass" function, which has a similar behavior to "getpass", including not providing a terminal feedback for passwords. The login uses pam_authenticate, which similarly does not provide a terminal feedback during password authentication. |
The "passwd", "login", and "sudo" commands on the system does not print any characters that are entered as a password. | ||||
| 482 | CCI-002891 | SRG-OS-000395-GPOS-00175 | The operating system must verify remote disconnection at the termination of nonlocal maintenance and diagnostic sessions, when used for nonlocal maintenance sessions. | Red Hat Enterprise Linux 9 must verify remote disconnection at the termination of nonlocal maintenance and diagnostic sessions, when used for nonlocal maintenance sessions. | If the remote connection is not closed and verified as closed, the session may remain open and be exploited by an attacker; this is referred to as a zombie session. Remote connections must be disconnected and verified as disconnected when nonlocal maintenance sessions have been terminated and are no longer available for use. | Applicable - Inherently Met | Verify the operating system verifies remote disconnection at the termination of nonlocal maintenance and diagnostic sessions, when used for nonlocal maintenance sessions. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. | Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. | CAT II | When a process terminates, Linux kernel executes the kernel/exit.c:do_exit() function which indirectly calls fs/file.c:close_files(). The latter iterates over all file descriptors of the process and close them. Since a socket also receives a file descriptor, the kernel close those, as well. | The use of the "exit" command will end any communication session on the system. This is part of the kernel and cannot be removed without recompiling. | |||||
| 483 | CCI-004047 | SRG-OS-000705-GPOS-00150 | The operating system must implement multifactor authentication for local, network, and/or remote access to privileged accounts and/or nonprivileged accounts such that the device meets organization-defined strength of mechanism requirements. | Red Hat Enterprise Linux 9 must implement multifactor authentication for local, network, and/or remote access to privileged accounts and/or nonprivileged accounts such that the device meets organization-defined strength of mechanism requirements. | The purpose of requiring a device separate from the system to which the user is attempting to gain access for one of the factors during multifactor authentication is to reduce the likelihood of compromising authenticators or credentials stored on the system. Adversaries may be able to compromise such authenticators or credentials and subsequently impersonate authorized users. Implementing one of the factors on a separate device (e.g., a hardware token), provides a greater strength of mechanism and an increased level of assurance in the authentication process. | pending | Verify the operating system is configured to implement multifactor authentication for local, network, and/or remote access to privileged accounts and/or nonprivileged accounts such that the device meets organization-defined strength of mechanism requirements. If the operating system is not configured to implement multifactor authentication for local, network, and/or remote access to privileged accounts and/or nonprivileged accounts such that the device meets organization-defined strength of mechanism requirements, this is a finding. |
CAT II | |||||||||
| 484 | CCI-002007 | SRG-OS-000383-GPOS-00166 | CCE-87996-5 | The operating system must prohibit the use of cached authenticators after one day. | Red Hat Enterprise Linux 9 must prohibit the use of cached authenticators after one day. | If cached authentication information is out-of-date, the validity of the authentication information may be questionable. | If cached authentication information is out-of-date, the validity of the authentication information may be questionable. | Applicable - Configurable | Verify the operating system prohibits the use of cached authenticators after one day. If it does not, this is a finding. | Verify that the System Security Services Daemon (SSSD) prohibits the use of cached authentications after one day. Note: If smart card authentication is not being used on the system, this requirement is Not Applicable. Check that SSSD allows cached authentications with the following command: $ sudo grep cache_credentials /etc/sssd/sssd.conf cache_credentials = true If "cache_credentials" is set to "false" or missing from the configuration file, this is not a finding and no further checks are required. If "cache_credentials" is set to "true", check that SSSD prohibits the use of cached authentications after one day with the following command: $ sudo grep offline_credentials_expiration /etc/sssd/sssd.conf offline_credentials_expiration = 1 If "offline_credentials_expiration" is not set to a value of "1", this is a finding. |
Configure the SSSD to prohibit the use of cached authentications after one day. Add or change the following line in "/etc/sssd/sssd.conf" just below the line [pam]: offline_credentials_expiration = 1 |
CAT II | |||||
| 485 | CCI-001443,CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000300-GPOS-00118 | CCE-84067-8 | The operating system must protect wireless access to the system using authentication of users and/or devices. | Red Hat Enterprise Linux 9 Bluetooth must be disabled. | Allowing devices and users to connect to the system without first authenticating them allows untrusted access and can lead to a compromise or attack. Wireless technologies include, for example, microwave, packet radio (UHF/VHF), 802.11x, and Bluetooth. Wireless networks use authentication protocols (e.g., EAP/TLS, PEAP), which provide credential protection and mutual authentication. This requirement applies to those operating systems that control wireless devices. |
This requirement applies to wireless peripheral technologies (e.g., wireless mice, keyboards, displays, etc.) used with Red Hat Enterprise Linux 9 systems. Wireless peripherals (e.g., Wi-Fi/Bluetooth/IR keyboards, mice and pointing devices, and near field communications [NFC]) present a unique challenge by creating an open, unsecured port on a computer. Wireless peripherals must meet DOD requirements for wireless data transmission and be approved for use by the Authorizing Official (AO). Even though some wireless peripherals, such as mice and pointing devices, do not ordinarily carry information that need to be protected, modification of communications with these wireless peripherals may be used to compromise the Red Hat Enterprise Linux 9 operating system. | Applicable - Configurable | Verify the operating system protects wireless access to the system using authentication of users and/or devices. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the ability to load the Bluetooth kernel module with the following command: $ sudo grep -r bluetooth /etc/modprobe.conf /etc/modprobe.d/* blacklist bluetooth If the command does not return any output, or the line is commented out, and use of Bluetooth is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
Configure Red Hat Enterprise Linux 9 to disable the Bluetooth adapter when not in use. Create or modify the "/etc/modprobe.d/bluetooth.conf" file with the following line: install bluetooth /bin/false blacklist bluetooth Reboot the system for the settings to take effect. |
CAT II | |||||
| 486 | CCI-002824,CCI-000381 | SRG-OS-000433-GPOS-00193,SRG-OS-000095-GPOS-00049 | CCE-83843-3 | The operating system must implement address space layout randomization to protect its memory from unauthorized code execution. | Red Hat Enterprise Linux 9 must enable mitigations against processor-based vulnerabilities. | Some adversaries launch attacks with the intent of executing code in non-executable regions of memory or in memory locations that are prohibited. Security safeguards employed to protect memory include, for example, data execution prevention and address space layout randomization. Data execution prevention safeguards can either be hardware-enforced or software-enforced with hardware providing the greater strength of mechanism. Examples of attacks are buffer overflow attacks. |
Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR). | Applicable - Configurable | Verify the operating system implements address space layout randomization to protect its memory from unauthorized code execution. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 enables kernel page-table isolation with the following command: $ sudo grubby --info=ALL | grep pti args="ro crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on If the "pti" entry does not equal "on", or is missing, this is a finding. Check that kernel page-table isolation is enabled by default to persist in kernel updates: $ sudo grep pti /etc/default/grub GRUB_CMDLINE_LINUX="pti=on" If "pti" is not set to "on", is missing or commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enable kernel page-table isolation with the following command: $ sudo grubby --update-kernel=ALL --args="pti=on" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="pti=on" |
CAT II | |||||
| 487 | CCI-000366 | SRG-OS-000480-GPOS-00226 | CCE-83635-3 | The operating system must enforce a delay of at least 4 seconds between logon prompts following a failed logon attempt. | Red Hat Enterprise Linux 9 must enforce a delay of at least four seconds between logon prompts following a failed logon attempt. | Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account. | Increasing the time between a failed authentication attempt and re-prompting to enter credentials helps to slow a single-threaded brute force attack. |
Applicable - Configurable | Verify the operating system enforces a delay of at least 4 seconds between logon prompts following a failed logon attempt. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 enforces a delay of at least four seconds between console logon prompts following a failed logon attempt with the following command: $ grep -i fail_delay /etc/login.defs FAIL_DELAY 4 If the value of "FAIL_DELAY" is not set to "4" or greater, or the line is commented out, this is a finding. |
Configure the Red Hat Enterprise Linux 9 to enforce a delay of at least 4 seconds between logon prompts following a failed console logon attempt. Modify the "/etc/login.defs" file to set the "FAIL_DELAY" parameter to 4 or greater: FAIL_DELAY 4 |
CAT II | |||||
| 488 | CCI-000172,CCI-002884 | SRG-OS-000064-GPOS-00033,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-OS-000468-GPOS-00212,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-88011-2 | The operating system must audit all activities performed during nonlocal maintenance and diagnostic sessions. | If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch. |
Applicable - Configurable | Verify the operating system audits all activities performed during nonlocal maintenance and diagnostic sessions. If it does not, this is a finding. | CAT II | |||||||||
| 489 | CCI-000172,CCI-002884 | SRG-OS-000064-GPOS-00033,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-OS-000468-GPOS-00212,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-87670-6 | The operating system must audit all activities performed during nonlocal maintenance and diagnostic sessions. | If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch. |
Applicable - Configurable | Verify the operating system audits all activities performed during nonlocal maintenance and diagnostic sessions. If it does not, this is a finding. | CAT II | |||||||||
| 490 | CCI-000172,CCI-002884 | SRG-OS-000064-GPOS-00033,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-OS-000468-GPOS-00212,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-85917-3 | The operating system must audit all activities performed during nonlocal maintenance and diagnostic sessions. | If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch. |
Applicable - Configurable | Verify the operating system audits all activities performed during nonlocal maintenance and diagnostic sessions. If it does not, this is a finding. | CAT II | |||||||||
| 491 | CCI-000172,CCI-002884 | SRG-OS-000064-GPOS-00033,SRG-OS-000392-GPOS-00172,SRG-OS-000458-GPOS-00203,SRG-OS-000461-GPOS-00205,SRG-OS-000468-GPOS-00212,SRG-APP-000501-CTR-001265,SRG-APP-000502-CTR-001270 | CCE-90754-3 | The operating system must audit all activities performed during nonlocal maintenance and diagnostic sessions. | If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the Internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch. |
Applicable - Configurable | Verify the operating system audits all activities performed during nonlocal maintenance and diagnostic sessions. If it does not, this is a finding. | CAT II | |||||||||
| 492 | CCI-003628 | SRG-OS-000590-GPOS-00110 | The operating system must disable accounts when the accounts are no longer associated to a user. | Red Hat Enterprise Linux 9 must disable accounts when the accounts are no longer associated to a user. | Disabling expired, inactive, or otherwise anomalous accounts supports the concepts of least privilege and least functionality which reduce the attack surface of the system. | pending | Verify the operating system is configured to disable accounts when the accounts are no longer associated to a user. If the operating system is not configured to disable accounts when the accounts are no longer associated to a user, this is a finding. |
CAT II | |||||||||
| 493 | CCI-000048,CCI-001384,CCI-001385,CCI-001386,CCI-001387,CCI-001388 | SRG-OS-000023-GPOS-00006,SRG-OS-000228-GPOS-00088 | CCE-86529-5 | The operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting local or remote access to the system. | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via logon interfaces with human users and are not required when such human interfaces do not exist. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've readconsent to terms in IS user agreem't." |
Applicable - Configurable | Verify the operating system displays the Standard Mandatory DoD Notice and Consent Banner before granting access to the system. The banner must be formatted in accordance with applicable DoD policy. Use the following verbiage for operating systems that can accommodate banners of 1300 characters: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Use the following verbiage for operating systems that have severe limitations on the number of characters that can be displayed in the banner: "I've read & consent to terms in IS user agreem't." If it does not, this is a finding. |
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| 494 | CCI-004064 | SRG-OS-000725-GPOS-00180 | The operating system must for password-based authentication, allow user selection of long passwords and passphrases, including spaces and all printable characters. | Red Hat Enterprise Linux 9 must for password-based authentication, allow user selection of long passwords and passphrases, including spaces and all printable characters. | Password-based authentication applies to passwords regardless of whether they are used in single-factor or multifactor authentication. Long passwords or passphrases are preferable over shorter passwords. Enforced composition rules provide marginal security benefits while decreasing usability. However, organizations may choose to establish certain rules for password generation (e.g., minimum character length for long passwords) under certain circumstances and can enforce this requirement in IA-5(1)(h). Account recovery can occur, for example, in situations when a password is forgotten. Cryptographically protected passwords include salted one-way cryptographic hashes of passwords. The list of commonly used, compromised, or expected passwords includes passwords obtained from previous breach corpuses, dictionary words, and repetitive or sequential characters. The list includes context-specific words, such as the name of the service, username, and derivatives thereof. | pending | Verify the operating system is configured to allow user selection of long passwords and passphrases, including spaces and all printable characters for password-based authentication. If the operating system is not configured to allow user selection of long passwords and passphrases, including spaces and all printable characters for password-based authentication, this is a finding. |
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| 495 | CCI-001889 | SRG-OS-000358-GPOS-00145 | The operating system must record time stamps for audit records that meet a minimum granularity of one second for a minimum degree of precision. | Red Hat Enterprise Linux 9 must record time stamps for audit records that meet a minimum granularity of one second for a minimum degree of precision. | Without sufficient granularity of time stamps, it is not possible to adequately determine the chronological order of records. Time stamps generated by the operating system include date and time. Granularity of time measurements refers to the degree of synchronization between information system clocks and reference clocks. |
Without sufficient granularity of time stamps, it is not possible to adequately determine the chronological order of records. Time stamps generated by the operating system include date and time. Granularity of time measurements refers to the degree of synchronization between information system clocks and reference clocks. |
Applicable - Inherently Met | Verify the operating system records time stamps for audit records that meet a minimum granularity of one second for a minimum degree of precision. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | Linux kernel audit subsystem always adds a timestamp to each audit buffer used to contain the entire audit log data. Function kernel/audit.c:audit_log_start() calls kernel/audit.c:audit_get_stamp() to fetch the timestamp and formats the message into the audit log buffer. |
The Red Hat Enterprise Linux 9 clock is part of the Linux kernel and is driven by a timer interrupt. The "ntp_adjtime" only allows for two modes of operation: "ntp_adjtime" or "adj_nano". |
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| 496 | CCI-001090 | SRG-OS-000138-GPOS-00069 | CCE-83895-3 | Operating systems must prevent unauthorized and unintended information transfer via shared system resources. | A sticky bit must be set on all Red Hat Enterprise Linux 9 public directories. | Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. |
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. |
Applicable - Configurable | Verify operating systems prevents unauthorized and unintended information transfer via shared system resources. If it does not, this is a finding. | Verify that all world-writable directories have the sticky bit set. Determine if all world-writable directories have the sticky bit set by running the following command: $ sudo find / -type d \( -perm -0002 -a ! -perm -1000 \) -print 2>/dev/null drwxrwxrwt 7 root root 4096 Jul 26 11:19 /tmp If any of the returned directories are world-writable and do not have the sticky bit set, this is a finding. |
Configure all world-writable directories to have the sticky bit set to prevent unauthorized and unintended information transferred via shared system resources. Set the sticky bit on all world-writable directories using the command, replace "[World-Writable Directory]" with any directory path missing the sticky bit: $ chmod a+t [World-Writable Directory] |
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| 497 | CCI-001082,CCI-001090 | SRG-OS-000132-GPOS-00067,SRG-OS-000138-GPOS-00069,SRG-APP-000243-CTR-000600 | CCE-83952-2 | Operating systems must prevent unauthorized and unintended information transfer via shared system resources. | Red Hat Enterprise Linux 9 must restrict access to the kernel message buffer. | Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. |
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user. |
Applicable - Configurable | Verify operating systems prevents unauthorized and unintended information transfer via shared system resources. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to restrict access to the kernel message buffer with the following commands: Check the status of the kernel.dmesg_restrict kernel parameter. $ sudo sysctl kernel.dmesg_restrict kernel.dmesg_restrict = 1 If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.dmesg_restrict | tail -1 kernel.dmesg_restrict = 1 If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to restrict access to the kernel message buffer. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: kernel.dmesg_restrict = 1 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 498 | CCI-001082,CCI-001090 | SRG-OS-000132-GPOS-00067,SRG-OS-000138-GPOS-00069,SRG-APP-000243-CTR-000600 | CCE-83959-7 | Operating systems must prevent unauthorized and unintended information transfer via shared system resources. | Red Hat Enterprise Linux 9 must prevent kernel profiling by nonprivileged users. | Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DoD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. |
Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Setting the kernel.perf_event_paranoid kernel parameter to "2" prevents attackers from gaining additional system information as a nonprivileged user. |
Applicable - Configurable | Verify operating systems prevents unauthorized and unintended information transfer via shared system resources. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to prevent kernel profiling by nonprivileged users with the following commands: Check the status of the kernel.perf_event_paranoid kernel parameter. $ sudo sysctl kernel.perf_event_paranoid kernel.perf_event_paranoid = 2 If "kernel.perf_event_paranoid" is not set to "2" or is missing, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F kernel.perf_event_paranoid | tail -1 kernel.perf_event_paranoid = 2 If "kernel.perf_event_paranoid" is not set to "2" or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent kernel profiling by nonprivileged users. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: kernel.perf_event_paranoid = 2 Load settings from all system configuration files with the following command: $ sudo sysctl --system |
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| 499 | CCI-004910 | SRG-OS-000780-GPOS-00240 | The operating system must provide protected storage for cryptographic keys with organization-defined safeguards and/or hardware protected key store. | Red Hat Enterprise Linux 9 must provide protected storage for cryptographic keys with organization-defined safeguards and/or hardware protected key store. | A Trusted Platform Module (TPM) is an example of a hardware-protected data store that can be used to protect cryptographic keys. | pending | Verify the operating system is configured to provide protected storage for cryptographic keys with organization-defined safeguards and/or hardware protected key store. If the operating system is not configured to provide protected storage for cryptographic keys with organization-defined safeguards and/or hardware protected key store, this is a finding. |
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| 500 | CCI-004066 | SRG-OS-000266-GPOS-00101 | CCE-83565-2 | The operating system must enforce password complexity by requiring that at least one special character be used. | Red Hat Enterprise Linux 9 must enforce password complexity by requiring that at least one special character be used. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity or strength is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor in determining how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Special characters are those characters that are not alphanumeric. Examples include: ~ ! @ # $ % ^ *. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Red Hat Enterprise Linux 9 utilizes "pwquality" as a mechanism to enforce password complexity. Note that to require special characters without degrading the "minlen" value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf". |
Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one special character be used. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces password complexity by requiring that at least one special character with the following command: $ sudo grep ocredit /etc/security/pwquality.conf /etc/security/pwquality.conf.d/*.conf ocredit = -1 If the value of "ocredit" is a positive number or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce password complexity by requiring that at least one special character be used by setting the "ocredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): ocredit = -1 |
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| 501 | CCI-000057,CCI-000060 | SRG-OS-000029-GPOS-00010,SRG-OS-000031-GPOS-00012 | CCE-86510-5 | The operating system must initiate a session lock after a 15-minute period of inactivity for all connection types. | Red Hat Enterprise Linux 9 must automatically lock graphical user sessions after 15 minutes of inactivity. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate a session lock. | Applicable - Configurable | Verify the operating system initiates a session lock after a 15-minute period of inactivity for all connection types. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 initiates a session lock after a 15-minute period of inactivity for graphical user interfaces with the following command: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ sudo gsettings get org.gnome.desktop.session idle-delay uint32 900 If "idle-delay" is set to "0" or a value greater than "900", this is a finding. |
Configure Red Hat Enterprise Linux 9 to initiate a screensaver after a 15-minute period of inactivity for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: $ sudo touch /etc/dconf/db/local.d/00-screensaver Edit /etc/dconf/db/local.d/00-screensaver and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 900 seconds before the session is considered idle idle-delay=uint32 900 Update the system databases: $ sudo dconf update |
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| 502 | CCI-000057,CCI-000060 | SRG-OS-000029-GPOS-00010,SRG-OS-000031-GPOS-00012 | CCE-85971-0 | The operating system must initiate a session lock after a 15-minute period of inactivity for all connection types. | Red Hat Enterprise Linux 9 must prevent a user from overriding the session idle-delay setting for the graphical user interface. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings. | Applicable - Configurable | Verify the operating system initiates a session lock after a 15-minute period of inactivity for all connection types. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i idle /etc/dconf/db/local.d/locks/* /org/gnome/desktop/session/idle-delay If the command does not return at least the example result, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/session/idle-delay |
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| 503 | CCI-000057 | SRG-OS-000029-GPOS-00010,SRG-OS-000031-GPOS-00012 | CCE-86954-5 | The operating system must initiate a session lock after a 15-minute period of inactivity for all connection types. | Red Hat Enterprise Linux 9 must initiate a session lock for graphical user interfaces when the screensaver is activated. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. |
A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to logout because of the temporary nature of the absence. | Applicable - Configurable | Verify the operating system initiates a session lock after a 15-minute period of inactivity for all connection types. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 initiates a session lock for graphical user interfaces when the screensaver is activated with the following command: Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. $ gsettings get org.gnome.desktop.screensaver lock-delay uint32 5 If the "uint32" setting is not set to "5" or less, or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to initiate a session lock for graphical user interfaces when a screensaver is activated. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/00-screensaver [org/gnome/desktop/screensaver] lock-delay=uint32 5 The "uint32" must be included along with the integer key values as shown. Update the system databases: $ sudo dconf update |
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| 504 | CCI-000057 | SRG-OS-000029-GPOS-00010,SRG-OS-000031-GPOS-00012 | CCE-87491-7 | The operating system must initiate a session lock after a 15-minute period of inactivity for all connection types. | Red Hat Enterprise Linux 9 must prevent a user from overriding the session lock-delay setting for the graphical user interface. | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems need to be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. |
A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not logout because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings. | Applicable - Configurable | Verify the operating system initiates a session lock after a 15-minute period of inactivity for all connection types. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the Red Hat Enterprise Linux 9 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is Not Applicable. Determine which profile the system database is using with the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification with the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-delay /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-delay If the command does not return at least the example result, this is a finding. |
Configure Red Hat Enterprise Linux 9 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the system-wide screensaver settings (if it does not already exist) with the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/screensaver/lock-delay |
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| 505 | CCI-001133,CCI-002361 | SRG-OS-000163-GPOS-00072,SRG-OS-000279-GPOS-00109 | CCE-90805-3 | The operating system must terminate all network connections associated with a communications session at the end of the session, or as follows: for in-band management sessions (privileged sessions), the session must be terminated after 10 minutes of inactivity; and for user sessions (non-privileged session), the session must be terminated after 15 minutes of inactivity, except to fulfill documented and validated mission requirements. | Red Hat Enterprise Linux 9 Must Terminate All Network Connections Associated With A Communications Session At The End Of The Session, Or As Follows: For In-Band Management Sessions (Privileged Sessions), The Session Must Be Terminated After 10 Minutes Of Inactivity; And For User Sessions (Non-Privileged Session), The Session Must Be Terminated After 15 Minutes Of Inactivity, Except To Fulfill Documented And Validated Mission Requirements. | Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level, and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. |
Terminating an idle SSH session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended. In addition, quickly terminating an idle SSH session will also free up resources committed by the managed network element. Terminating network connections associated with communications sessions includes, for example, de-allocating associated TCP/IP address/port pairs at the operating system level and de-allocating networking assignments at the application level if multiple application sessions are using a single operating system-level network connection. This does not mean that the operating system terminates all sessions or network access; it only ends the inactive session and releases the resources associated with that session. Red Hat Enterprise Linux 9 utilizes /etc/ssh/sshd_config for configurations of OpenSSH. Within the sshd_config the product of the values of "ClientAliveInterval" and "ClientAliveCountMax" are used to establish the inactivity threshold. The "ClientAliveInterval" is a timeout interval in seconds after which if no data has been received from the client, sshd will send a message through the encrypted channel to request a response from the client. The "ClientAliveCountMax" is the number of client alive messages that may be sent without sshd receiving any messages back from the client. If this threshold is met, sshd will disconnect the client. For more information on these settings and others, refer to the sshd_config man pages. |
Applicable - Configurable | Verify the operating system terminates all network connections associated with a communications session at the end of the session, or as follows: for in-band management sessions (privileged sessions), the session must be terminated after 10 minutes of inactivity; and for user sessions (non-privileged session), the session must be terminated after 15 minutes of inactivity, except to fulfill documented and validated mission requirements. If it does not, this is a finding. |
Verify that the "ClientAliveCountMax" is set to "1" by performing the following command: $ sudo grep -i countmax /etc/ssh/sshd_config ClientAliveCountMax 1 If "ClientAliveCountMax" do not exist, is not set to a value of "1" in "/etc/ssh/sshd_config", or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to automatically terminate all network connections associated with SSH traffic at the end of a session or after 10 minutes of inactivity. Modify or append the following lines in the "/etc/ssh/sshd_config" file: ClientAliveCountMax 0 In order for the changes to take effect, the SSH daemon must be restarted. $ sudo systemctl restart sshd.service |
CAT II | |||||
| 506 | CCI-000803,CCI-004062 | SRG-OS-000073-GPOS-00041 | CCE-83615-5 | The operating system must store only encrypted representations of passwords. | Red Hat Enterprise Linux 9 password-auth must be configured to use a sufficient number of hashing rounds. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. |
Applicable - Configurable | Verify the operating system stores only encrypted representations of passwords. If it does not, this is a finding. | Verify the number of rounds for the password hashing algorithm is configured with the following command: $ sudo grep rounds /etc/pam.d/password-auth password sufficient pam_unix.so sha512 rounds=5000 If a matching line is not returned or "rounds" is less than 5000, this a finding. |
Configure Red Hat Enterprise Linux 9 to use 5000 hashing rounds for hashing passwords. Add or modify the following line in "/etc/pam.d/password-auth" and set "rounds" to 5000 password sufficient pam_unix.so sha512 rounds=5000 |
CAT I | |||||
| 507 | CCI-000803,CCI-004062 | SRG-OS-000073-GPOS-00041 | CCE-83621-3 | The operating system must store only encrypted representations of passwords. | Red Hat Enterprise Linux 9 system-auth must be configured to use a sufficient number of hashing rounds. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. |
Applicable - Configurable | Verify the operating system stores only encrypted representations of passwords. If it does not, this is a finding. | Verify the number of rounds for the password hashing algorithm is configured with the following command: $ sudo grep rounds /etc/pam.d/system-auth password sufficient pam_unix.so sha512 rounds=5000 If a matching line is not returned or "rounds" is less than 5000, this a finding. |
Configure Red Hat Enterprise Linux 9 to use 5000 hashing rounds for hashing passwords. Add or modify the following line in "/etc/pam.d/system-auth" and set "rounds" to 5000. password sufficient pam_unix.so sha512 rounds=5000' |
CAT I | |||||
| 508 | CCI-004062 | SRG-OS-000073-GPOS-00041 | CCE-88865-1 | The operating system must store only encrypted representations of passwords. | Red Hat Enterprise Linux 9 must be configured so that user and group account administration utilities are configured to store only encrypted representations of passwords. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the "crypt_style" configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult. |
Applicable - Configurable | Verify the operating system stores only encrypted representations of passwords. If it does not, this is a finding. | Verify the user and group account administration utilities are configured to store only encrypted representations of passwords with the following command: # grep crypt /etc/libuser.conf crypt_style = sha512 If the "crypt_style" variable is not set to "sha512", is not in the defaults section, is commented out, or does not exist, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use the SHA-512 algorithm for password hashing. Add or change the following line in the "[default]" section of "/etc/libuser.conf" file: crypt_style = sha512 |
CAT I | |||||
| 509 | CCI-004062 | SRG-OS-000073-GPOS-00041 | CCE-90590-1 | The operating system must store only encrypted representations of passwords. | Red Hat Enterprise Linux 9 must be configured to use the shadow file to store only encrypted representations of passwords. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kepy in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the "crypt_style" configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult. |
Applicable - Configurable | Verify the operating system stores only encrypted representations of passwords. If it does not, this is a finding. | Verify the system's shadow file is configured to store only encrypted representations of passwords. with a hash value of SHA512 with the following command: # grep -i encrypt_method /etc/login.defs ENCRYPT_METHOD SHA512 If "ENCRYPT_METHOD" does not have a value of "SHA512", or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to store only SHA512 encrypted representations of passwords. Add or update the following line in the "/etc/login.defs" file: ENCRYPT_METHOD SHA512 |
CAT I | |||||
| 510 | CCI-000803,CCI-004062 | SRG-OS-000073-GPOS-00041,SRG-OS-000120-GPOS-00061 | CCE-89708-2 | The operating system must store only encrypted representations of passwords. | Red Hat Enterprise Linux 9 shadow password suite must be configured to use a sufficient number of hashing rounds. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. |
Applicable - Configurable | Verify the operating system stores only encrypted representations of passwords. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 has a minimum number of hash rounds configured with the following command: $ grep -i sha_crypt /etc/login.defs If "SHA_CRYPT_MIN_ROUNDS" or "SHA_CRYPT_MAX_ROUNDS" is less than "5000", this is a finding. |
Configure Red Hat Enterprise Linux 9 to encrypt all stored passwords with a strong cryptographic hash. Edit/modify the following line in the "/etc/login.defs" file and set "SHA_CRYPT_MIN_ROUNDS" to a value no lower than "5000": SHA_CRYPT_MIN_ROUNDS 5000 |
CAT I | |||||
| 511 | CCI-001941 | SRG-OS-000113-GPOS-00058 | The operating system must implement replay-resistant authentication mechanisms for network access to nonprivileged accounts. | Red Hat Enterprise Linux 9 must implement replay-resistant authentication mechanisms for network access to nonprivileged accounts. | A replay attack may enable an unauthorized user to gain access to the operating system. Authentication sessions between the authenticator and the operating system validating the user credentials must not be vulnerable to a replay attack. An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. A nonprivileged account is any operating system account with authorizations of a nonprivileged user. Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. |
Applicable - Inherently Met | Verify the operating system implements replay-resistant authentication mechanisms for network access to nonprivileged accounts. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | The release notes of OpenSSH 7.6 states "OpenSSH is a 100% complete SSH protocol 2.0 implementation and includes sftp client and server support." https://www.openssh.com/txt/release-7.6 |
The OpenSSH package in Red Hat Enterprise Linux 9 is version 9.6, which is newer than 7.6 which only supports SSH protocol 2.0 which is restraint to replay attacks. | |||||
| 512 | CCI-004066 | SRG-OS-000070-GPOS-00038 | CCE-83570-2 | The operating system must enforce password complexity by requiring that at least one lowercase character be used. | Red Hat Enterprise Linux 9 must enforce password complexity by requiring that at least one lower-case character be used. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space. |
Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one lowercase character be used. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces password complexity by requiring that at least one lower-case character. Check the value for "lcredit" with the following command: $ sudo grep lcredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:lcredit = -1 If the value of "lcredit" is a positive number or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce password complexity by requiring that at least one lower-case character be used by setting the "lcredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): lcredit = -1 |
CAT II | |||||
| 513 | CCI-001453 | SRG-OS-000250-GPOS-00093 | CCE-83452-3 | The operating system must implement cryptography to protect the integrity of remote access sessions. | Red Hat Enterprise Linux 9 must implement DOD-approved encryption in the OpenSSL package. | Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. |
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/openssl.config file. |
Applicable - Configurable | Verify the operating system implements cryptography to protect the integrity of remote access sessions. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 OpenSSL library is configured to use only ciphers employing FIPS 140-3 approved algorithms with the following command: $ sudo grep -i opensslcnf.config /etc/pki/tls/openssl.cnf .include = /etc/crypto-policies/back-ends/opensslcnf.config If the "opensslcnf.config" is not defined in the "/etc/pki/tls/openssl.cnf" file, this is a finding. |
Configure the Red Hat Enterprise Linux 9 OpenSSL library to use the system cryptographic policy. Edit the "/etc/pki/tls/openssl.cnf" and add or modify the following line: .include = /etc/crypto-policies/back-ends/opensslcnf.config |
CAT I | |||||
| 514 | CCI-001453 | SRG-OS-000125-GPOS-00065,SRG-OS-000250-GPOS-00093,SRG-OS-000393-GPOS-00173,SRG-OS-000394-GPOS-00174 | CCE-83448-1 | The operating system must implement cryptography to protect the integrity of remote access sessions. | Red Hat Enterprise Linux 9 must implement DOD-approved TLS encryption in the OpenSSL package. | Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. |
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/openssl.config file. |
Applicable - Configurable | Verify the operating system implements cryptography to protect the integrity of remote access sessions. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 OpenSSL library is configured to use TLS 1.2 encryption or stronger with following command: $ grep -i minprotocol /etc/crypto-policies/back-ends/opensslcnf.config TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 If the "TLS.MinProtocol" is set to anything older than "TLSv1.2" or the "DTLS.MinProtocol" is set to anything older than "DTLSv1.2", this is a finding. |
Configure the Red Hat Enterprise Linux 9 OpenSSL library to use only DOD-approved TLS encryption by editing the following line in the "/etc/crypto-policies/back-ends/opensslcnf.config" file: TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 A reboot is required for the changes to take effect. |
CAT I | |||||
| 515 | CCI-001453 | SRG-OS-000250-GPOS-00093 | CCE-83445-7 | The operating system must implement cryptography to protect the integrity of remote access sessions. | Red Hat Enterprise Linux 9 SSH daemon must be configured to use system-wide crypto policies. | Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. |
Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. |
Applicable - Configurable | Verify the operating system implements cryptography to protect the integrity of remote access sessions. If it does not, this is a finding. | Verify that systemwide crypto policies are in effect with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr ' ' ' ' | xargs sudo grep -iH '^\s*include' /etc/ssh/sshd_config:Include /etc/ssh/sshd_config.d/*.conf /etc/ssh/sshd_config.d/50-redhat.conf:Include /etc/crypto-policies/back-ends/opensshserver.config If "Include /etc/ssh/sshd_config.d/*.conf" or "Include /etc/crypto-policies/back-ends/opensshserver.config" are not included in the system sshd config or the file /etc/ssh/sshd_config.d/50-redhat.conf is missing, this is a finding. |
Configure the Red Hat Enterprise Linux 9 SSH daemon to use system-wide crypto policies by running the following commands: $ sudo dnf reinstall openssh-server |
CAT I | |||||
| 516 | CCI-000067 | SRG-OS-000032-GPOS-00013 | CCE-86923-0 | The operating system must monitor remote access methods. | Red Hat Enterprise Linux 9 must log SSH connection attempts and failures to the server. | Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyber attacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). |
SSH provides several logging levels with varying amounts of verbosity. "DEBUG" is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. "INFO" or "VERBOSE" level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field. | Applicable - Configurable | Verify the operating system monitors remote access methods. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 logs SSH connection attempts and failures to the server. Check what the SSH daemon's "LogLevel" option is set to with the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '' ' ' | xargs sudo grep -iH '^\s*loglevel' LogLevel VERBOSE If a value of "VERBOSE" is not returned or the line is commented out or missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to log connection attempts add or modify the following line in "/etc/ssh/sshd_config". LogLevel VERBOSE Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service |
CAT II | |||||
| 517 | CCI-000067 | SRG-OS-000032-GPOS-00013 | CCE-87960-1 | The operating system must monitor remote access methods. | All Red Hat Enterprise Linux 9 remote access methods must be monitored. | Remote access services, such as those providing remote access to network devices and information systems, which lack automated monitoring capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Automated monitoring of remote access sessions allows organizations to detect cyber attacks and also ensure ongoing compliance with remote access policies by auditing connection activities of remote access capabilities, such as Remote Desktop Protocol (RDP), on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). |
Logging remote access methods can be used to trace the decrease in the risks associated with remote user access management. It can also be used to spot cyberattacks and ensure ongoing compliance with organizational policies surrounding the use of remote access methods. | Applicable - Configurable | Verify the operating system monitors remote access methods. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 monitors all remote access methods. Check that remote access methods are being logged by running the following command: $ grep -rE '(auth.\*|authpriv.\*|daemon.\*)' /etc/rsyslog.conf /etc/rsyslog.conf:authpriv.* If "auth.*", "authpriv.*" or "daemon.*" are not configured to be logged, this is a finding. |
Add or update the following lines to the "/etc/rsyslog.conf" file: auth.*;authpriv.*;daemon.* /var/log/secure The "rsyslog" service must be restarted for the changes to take effect with the following command: $ sudo systemctl restart rsyslog.service |
CAT II | |||||
| 518 | CCI-001855 | SRG-OS-000343-GPOS-00134 | CCE-83700-5 | The operating system must immediately notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. | Red Hat Enterprise Linux 9 must take action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity. | If security personnel are not notified immediately when storage volume reaches 75% utilization, they are unable to plan for audit record storage capacity expansion. | If action is not taken when storage volume reaches 95% utilization the auditing system may fail when the storage volume reaches capacity. | Applicable - Configurable | Verify the operating system immediately notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to take action in the event of allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity with the following command: $ sudo grep admin_space_left_action /etc/audit/auditd.conf admin_space_left_action = single If the value of the "admin_space_left_action" is not set to "single", or if the line is commented out, ask the System Administrator to indicate how the system is providing real-time alerts to the SA and ISSO. If there is no evidence that real-time alerts are configured on the system, this is a finding. |
Configure "auditd" service to take action in the event of allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity. Edit the following line in "/etc/audit/auditd.conf" to ensure that the system is forced into single user mode in the event the audit record storage volume is about to reach maximum capacity: admin_space_left_action = single The audit daemon must be restarted for changes to take effect. |
CAT III | |||||
| 519 | CCI-001855 | SRG-OS-000343-GPOS-00134 | CCE-88816-4 | The operating system must immediately notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. | If security personnel are not notified immediately when storage volume reaches 75% utilization, they are unable to plan for audit record storage capacity expansion. | Applicable - Configurable | Verify the operating system immediately notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity. If it does not, this is a finding. | CAT III | |||||||||
| 520 | CCI-001855 | SRG-OS-000343-GPOS-00134 | CCE-83703-9 | The operating system must immediately notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. | Red Hat Enterprise Linux 9 must notify the System Administrator (SA) and Information System Security Officer (ISSO) (at a minimum) when allocated audit record storage volume 75 percent utilization. | If security personnel are not notified immediately when storage volume reaches 75% utilization, they are unable to plan for audit record storage capacity expansion. | If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion. | Applicable - Configurable | Verify the operating system immediately notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity with the following command: $ sudo grep -w space_left_action /etc/audit/auditd.conf space_left_action = email If the value of the "space_left_action" is not set to "email", or if the line is commented out, ask the System Administrator to indicate how the system is providing real-time alerts to the SA and ISSO. If there is no evidence that real-time alerts are configured on the system, this is a finding. |
Configure Red Hat Enterprise Linux 9 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file. space_left_action = email |
CAT III | |||||
| 521 | CCI-001855 | SRG-OS-000343-GPOS-00134 | CCE-87746-4 | The operating system must immediately notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. | Red Hat Enterprise Linux 9 must take action when allocated audit record storage volume reaches 95 percent of the audit record storage capacity. | If security personnel are not notified immediately when storage volume reaches 75% utilization, they are unable to plan for audit record storage capacity expansion. | If action is not taken when storage volume reaches 95% utilization the auditing system may fail when the storage volume reaches capacity. | Applicable - Configurable | Verify the operating system immediately notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 takes action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity with the following command: $ sudo grep -w admin_space_left /etc/audit/auditd.conf admin_space_left = 5% If the value of the "admin_space_left" keyword is not set to 5% of the storage volume allocated to audit logs, or if the line is commented out, ask the System Administrator to indicate how the system is taking action if the allocated storage is about to reach capacity. If the "space_left" value is not configured to the correct value, this is a finding. |
Configure Red Hat Enterprise Linux 9 to initiate an action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file. admin_space_left = 5% |
CAT III | |||||
| 522 | CCI-004066 | SRG-OS-000069-GPOS-00037,SRG-OS-000480-GPOS-00227 | CCE-83569-4 | The operating system must enforce password complexity by requiring that at least one uppercase character be used. | Red Hat Enterprise Linux 9 must ensure the password complexity module in the system-auth file is configured for three retries or less. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. Red Hat Enterprise Linux 9 uses "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes. |
Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one uppercase character be used. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 is configured to limit the "pwquality" retry option to 3. Check for the use of the "pwquality" retry option in the system-auth file with the following command: $ cat /etc/pam.d/system-auth | grep pam_pwquality password required pam_pwquality.so retry=3 If the value of "retry" is set to "0" or greater than "3", or is missing, this is a finding. |
Configure Red Hat Enterprise Linux 9 to limit the "pwquality" retry option to 3. Add the following line to the "/etc/pam.d/system-auth" file (or modify the line to have the required value): password required pam_pwquality.so retry=3 |
CAT II | |||||
| 523 | CCI-004066 | SRG-OS-000069-GPOS-00037,SRG-OS-000070-GPOS-00038 | CCE-83568-6 | The operating system must enforce password complexity by requiring that at least one uppercase character be used. | Red Hat Enterprise Linux 9 must enforce password complexity by requiring that at least one upper-case character be used. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possble combinations that need to be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space. |
Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one uppercase character be used. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 enforces password complexity by requiring that at least one upper-case character. Check the value for "ucredit" with the following command: $ sudo grep ucredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf ucredit = -1 If the value of "ucredit" is a positive number or is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to enforce password complexity by requiring that at least one upper-case character be used by setting the "ucredit" option. Add the following line to /etc/security/pwquality.conf (or modify the line to have the required value): ucredit = -1 |
CAT II | |||||
| 524 | CCI-004066 | SRG-OS-000069-GPOS-00037,SRG-OS-000070-GPOS-00038,SRG-OS-000480-GPOS-00227 | CCE-85878-7 | The operating system must enforce password complexity by requiring that at least one uppercase character be used. | Red Hat Enterprise Linux 9 must ensure the password complexity module is enabled in the password-auth file. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks. | Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one uppercase character be used. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 uses "pwquality" to enforce the password complexity rules in the password-auth file with the following command: $ cat /etc/pam.d/password-auth | grep pam_pwquality password required pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/password-auth" file (or modify the line to have the required value): password required pam_pwquality.so |
CAT II | |||||
| 525 | CCI-000366 | SRG-OS-000480-GPOS-00227 | CCE-85873-8 | The operating system must enforce password complexity by requiring that at least one uppercase character be used. | Red Hat Enterprise Linux 9 must ensure the password complexity module is enabled in the system-auth file. | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. |
Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks. | Applicable - Configurable | Verify the operating system enforces password complexity by requiring that at least one uppercase character be used. If it does not, this is a finding. | Verify Red Hat Enterprise Linux 9 uses "pwquality" to enforce the password complexity rules in the system-auth file with the following command: $ cat /etc/pam.d/system-auth | grep pam_pwquality password required pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/system-auth" file(or modify the line to have the required value): password required pam_pwquality.so |
CAT II | |||||
| 526 | CCI-000015 | SRG-OS-000274-GPOS-00104 | The operating system must notify system administrators and ISSOs when accounts are created. | Red Hat Enterprise Linux 9 must notify system administrators and ISSOs when accounts are created. | Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to create a new account. Notification of account creation is one method for mitigating this risk. A comprehensive account management process will ensure an audit trail which documents the creation of operating system user accounts and notifies administrators and ISSOs that it exists. Such a process greatly reduces the risk that accounts will be surreptitiously created and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to create a new account. Notification of account creation is one method for mitigating this risk. A comprehensive account management process will ensure an audit trail that documents the creation of operating system user accounts and notifies administrators and ISSOs that it exists. Such a process greatly reduces the risk that accounts will be surreptitiously created and provides logging that can be used for forensic purposes. To address access requirements, many operating systems can be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements. |
Applicable - Does Not Meet | Verify the operating system notifies System Administrators and Information System Security Officers when accounts are created. If it does not, this is a finding. | Red Hat Enterprise Linux 9 does not support this requirement. This is an applicable-does not meet finding. |
This requirement is a permanent finding and cannot be fixed. An appropriate mitigation for the system must be implemented, but this finding cannot be considered fixed. |
CAT II | Mitigate with third-party software. Although the listed mitigation is supporting the security function, it is not sufficient to reduce the residual risk of this requirement. |
Notification when accounts are created/modified/deleted must be provided by a third-party application that will communicate that an audit record of these actions has been created. | ||||
| 527 | CCI-002165 | SRG-OS-000312-GPOS-00124 | The operating system must allow operating system admins to change security attributes on users, the operating system, or the operating systems components. | Red Hat Enterprise Linux 9 must allow operating system admins to change security attributes on users, the operating system, or the operating systems components. | Discretionary Access Control (DAC) is based on the notion that individual users are "owners" of objects and therefore have discretion over who should be authorized to access the object and in which mode (e.g., read or write). Ownership is usually acquired as a consequence of creating the object or via specified ownership assignment. DAC allows the owner to determine who will have access to objects they control. An example of DAC includes user-controlled file permissions. When discretionary access control policies are implemented, subjects are not constrained with regard to what actions they can take with information for which they have already been granted access. Thus, subjects that have been granted access to information are not prevented from passing (i.e., the subjects have the discretion to pass) the information to other subjects or objects. A subject that is constrained in its operation by Mandatory Access Control policies is still able to operate under the less rigorous constraints of this requirement. Thus, while Mandatory Access Control imposes constraints preventing a subject from passing information to another subject operating at a different sensitivity level, this requirement permits the subject to pass the information to any subject at the same sensitivity level. The policy is bounded by the information system boundary. Once the information is passed outside the control of the information system, additional means may be required to ensure the constraints remain in effect. While the older, more traditional definitions of discretionary access control require identity-based access control, that limitation is not required for this use of discretionary access control. |
Administrators of Red Hat Enterprise Linux 9 need to be able change attributes on users, the operating system, or Red Hat Enterprise Linux 9 components in order secure the system and ensure that the system is setup to perform the mission. |
Applicable - Inherently Met | Verify the operating system allows operating system admins to change security attributes on users, the operating system, or the operating system's components. If it does not, this is a finding. | Red Hat Enterprise Linux 9 supports this requirement and cannot be configured to be out of compliance. Red Hat Enterprise Linux 9 inherently meets this requirement. |
Red Hat Enterprise Linux 9 inherently meets this requirement. No fix is required. |
CAT II | UID 0 is the root account as defined by POSIX standard. The root user has the ability to full administrator Red Hat Enterprise Linux 9. | Red Hat Enterprise Linux 9 meets this requirement and it is not configurable. | ||||
| 528 | CCI-000381 | SRG-OS-000095-GPOS-00049 | CCE-84149-4 | The operating system must transmit only encrypted representations of passwords. | Red Hat Enterprise Linux 9 must not have the telnet-server package installed. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore, may remain unsecure. They increase the risk to the platform by providing additional attack vectors. The telnet service provides an unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised. Removing the "telnet-server" package decreases the risk of accidental (or intentional) activation of the telnet service. |
Applicable - Configurable | Verify the operating system transmits only encrypted representations of passwords. If it does not, this is a finding. | Verify that the telnet-server package is not installed with the following command: $ sudo dnf list --installed telnet-server Error: No matching Packages to list If the "telnet-server" package is installed, this is a finding. |
Remove the telnet-server package with the following command: $ sudo dnf remove telnet-server |
CAT I | |||||
| 529 | CCI-000197 | SRG-OS-000074-GPOS-00042 | CCE-84153-6 | The operating system must transmit only encrypted representations of passwords. | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. | Applicable - Configurable | Verify the operating system transmits only encrypted representations of passwords. If it does not, this is a finding. | CAT I | |||||||||
| 530 | CCI-000130 | SRG-APP-000029-CTR-000085 | The operating system must produce audit records containing information to establish what type of events occurred. | Red Hat Enterprise Linux 9 must audit all uses of the pkexec command. | Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in the operating system audit logs provides a means of investigating an attack; recognizing resource utilization or capacity thresholds; or identifying an improperly configured operating system. |
Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining syscalls into one rule whenever possible. |
Applicable - Configurable | Verify the operating system produces audit records containing information to establish what type of events occurred. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 is configured to audit the execution of the "pkexec" command with the following command: $ sudo auditctl -l | grep pkexec -a always,exit -F path=/usr/bin/pkexec -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pkexec If the command does not return a line, or the line is commented out, this is a finding. |
Configure Red Hat Enterprise Linux 9 to generate audit records upon successful/unsuccessful attempts to use the "pkexec" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/pkexec -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pkexec The audit daemon must be restarted for the changes to take effect. |
CAT II | ||||||
| 531 | CCI-003992 | SRG-OS-000366-GPOS-00153 | CCE-83506-6 | The operating system must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. | Red Hat Enterprise Linux 9 subscription-manager package must be installed. | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved CA. |
The Red Hat Subscription Manager application manages software subscriptions and software repositories for installed software products on the local system. It communicates with backend servers, such as the Red Hat Customer Portal or an on-premise instance of Subscription Asset Manager, to register the local system and grant access to software resources determined by the subscription entitlement. | Applicable - Configurable | Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 subscription-manager package is installed with the following command: $ sudo dnf list --installed subscription-manager Example output: subscription-manager.x86_64 1.29.26-3.el9_0 If the "subscription-manager" package is not installed, this is a finding. |
The subscription-manager package can be installed with the following command: $ sudo dnf install subscription-manager |
CAT I | |||||
| 532 | CCI-003992 | SRG-OS-000366-GPOS-00153 | CCE-83457-2 | The operating system must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. | Red Hat Enterprise Linux 9 must check the GPG signature of software packages originating from external software repositories before installation. | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved CA. |
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. |
Applicable - Configurable | Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. If it does not, this is a finding. | Verify that dnf always checks the GPG signature of software packages originating from external software repositories before installation: $ grep gpgcheck /etc/dnf/dnf.conf gpgcheck=1 If "gpgcheck" is not set to "1", or if the option is missing or commented out, ask the system administrator how the GPG signatures of software packages are being verified. If there is no process to verify GPG signatures that is approved by the organization, this is a finding. |
Configure dnf to always check the GPG signature of software packages originating from external software repositories before installation. Add or update the following line in the [main] section of the /etc/dnf/dnf.conf file: gpgcheck=1 |
CAT I | |||||
| 533 | CCI-003992 | SRG-OS-000366-GPOS-00153 | CCE-83463-0 | The operating system must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. | Red Hat Enterprise Linux 9 must check the GPG signature of locally installed software packages before installation. | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved CA. |
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. |
Applicable - Configurable | Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. If it does not, this is a finding. | Verify that dnf always checks the GPG signature of locally installed software packages before installation: $ grep localpkg_gpgcheck /etc/dnf/dnf.conf localpkg_gpgcheck=1 If "localpkg_gpgcheck" is not set to "1", or if the option is missing or commented out, ask the system administrator how the GPG signatures of local software packages are being verified. If there is no process to verify GPG signatures that is approved by the organization, this is a finding. |
Configure dnf to always check the GPG signature of local software packages before installation. Add or update the following line in the [main] section of the /etc/dnf/dnf.conf file: localpkg_gpgcheck=1 |
CAT I | |||||
| 534 | CCI-003992 | SRG-OS-000366-GPOS-00153 | CCE-83464-8 | The operating system must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. | Red Hat Enterprise Linux 9 must have GPG signature verification enabled for all software repositories. | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved CA. |
Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. |
Applicable - Configurable | Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. If it does not, this is a finding. | Verify that all software repositories defined in "/etc/yum.repos.d/" have been configured with "gpgcheck" enabled: $ grep gpgcheck /etc/yum.repos.d/*.repo | more gpgcheck = 1 If "gpgcheck" is not set to "1" for all returned lines, this is a finding. |
Configure all software repositories defined in "/etc/yum.repos.d/" to have "gpgcheck" enabled: $ sudo sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/* |
CAT I | |||||
| 535 | CCI-003992 | SRG-OS-000366-GPOS-00153 | CCE-84180-9 | The operating system must prevent the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. | Red Hat Enterprise Linux 9 must ensure cryptographic verification of vendor software packages. | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. The operating system should not have to verify the software again. This requirement does not mandate DOD certificates for this purpose; however, the certificate used to verify the software must be from an approved CA. |
Cryptographic verification of vendor software packages ensures that all software packages are obtained from a valid source and protects against spoofing that could lead to installation of malware on the system. Red Hat cryptographically signs all software packages, which includes updates, with a GPG key to verify that they are valid. | Applicable - Configurable | Verify the operating system prevents the installation of patches, service packs, device drivers, or operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization. If it does not, this is a finding. | Confirm Red Hat package-signing keys are installed on the system and verify their fingerprints match vendor values. Note: For Red Hat Enterprise Linux 9 software packages, Red Hat uses GPG keys labeled "release key 2" and "auxiliary key 3". The keys are defined in key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" by default. List Red Hat GPG keys installed on the system: $ sudo rpm -q --queryformat "%{SUMMARY} " gpg-pubkey | grep -i "red hat" Red Hat, Inc. (release key 2) <security@redhat.com> public key Red Hat, Inc. (auxiliary key 3) <security@redhat.com> public key If Red Hat GPG keys "release key 2" and "auxiliary key 3" are not installed, this is a finding. List key fingerprints of installed Red Hat GPG keys: $ sudo gpg -q --keyid-format short --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release If key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" is missing, this is a finding. Example output: pub rsa4096/FD431D51 2009-10-22 [SC] Key fingerprint = 567E 347A D004 4ADE 55BA 8A5F 199E 2F91 FD43 1D51 uid Red Hat, Inc. (release key 2) <security@redhat.com> pub rsa4096/5A6340B3 2022-03-09 [SC] Key fingerprint = 7E46 2425 8C40 6535 D56D 6F13 5054 E4A4 5A63 40B3 uid Red Hat, Inc. (auxiliary key 3) <security@redhat.com> Compare key fingerprints of installed Red Hat GPG keys with fingerprints listed for Red Hat Enterprise Linux 9 on Red Hat "Product Signing Keys" webpage at https://access.redhat.com/security/team/key. If key fingerprints do not match, this is a finding. |
Install Red Hat package-signing keys on the system and verify their fingerprints match vendor values. Insert Red Hat Enterprise Linux 9 installation disc or attach Red Hat Enterprise Linux 9 installation image to the system. Mount the disc or image to make the contents accessible inside the system. Assuming the mounted location is "/media/cdrom", use the following command to copy Red Hat GPG key file onto the system: $ sudo cp /media/cdrom/RPM-GPG-KEY-redhat-release /etc/pki/rpm-gpg/ Import Red Hat GPG keys from key file into system keyring: $ sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release Using the steps listed in the Check Text, confirm the newly imported keys show as installed on the system and verify their fingerprints match vendor values. |
CAT I | |||||
| 536 | CCI-000381 | SRG-OS-000095-GPOS-00049 | CCE-84243-5 | The operating system must be configured to disable non-essential capabilities. | Red Hat Enterprise Linux 9 must not have the nfs-utils package installed. | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software, not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. |
"nfs-utils" provides a daemon for the kernel NFS server and related tools. This package also contains the "showmount" program. "showmount" queries the mount daemon on a remote host for information about the Network File System (NFS) server on the remote host. For example, "showmount" can display the clients that are mounted on that host. | Applicable - Configurable | Verify the operating system is configured to disable non-essential capabilities. If it does not, this is a finding. | Verify that the nfs-utils package is not installed with the following command: $ sudo dnf list --installed nfs-utils Error: No matching Packages to list If the "nfs-utils" package is installed, this is a finding. |
Remove the nfs-utils package with the following command: $ sudo dnf remove nfs-utils |
CAT II | |||||
| 537 | CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-84134-6 | The operating system must be configured to disable non-essential capabilities. | Red Hat Enterprise Linux 9 must be configured to disable the Controller Area Network kernel module. | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software, not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. |
Disabling Controller Area Network (CAN) protects the system against exploitation of any flaws in its implementation. | Applicable - Configurable | Verify the operating system is configured to disable non-essential capabilities. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the ability to load the CAN kernel module with the following command: $ sudo grep -r can /etc/modprobe.conf /etc/modprobe.d/* blacklist can If the command does not return any output, or the line is commented out, and use of CAN is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
To configure the system to prevent the can kernel module from being loaded, add the following line to the file /etc/modprobe.d/can.conf (or create atm.conf if it does not exist): install can /bin/false blacklist can |
CAT II | |||||
| 538 | CCI-000381 | SRG-OS-000095-GPOS-00049,SRG-OS-000480-GPOS-00227 | CCE-84139-5 | The operating system must be configured to disable non-essential capabilities. | Red Hat Enterprise Linux 9 must disable the Stream Control Transmission Protocol (SCTP) kernel module. | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software, not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. |
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation. |
Applicable - Configurable | Verify the operating system is configured to disable non-essential capabilities. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the ability to load the sctp kernel module with the following command: $ sudo grep -r sctp /etc/modprobe.conf /etc/modprobe.d/* blacklist sctp If the command does not return any output, or the line is commented out, and use of sctp is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
To configure the system to prevent the sctp kernel module from being loaded, add the following line to the file /etc/modprobe.d/sctp.conf (or create sctp.conf if it does not exist): install sctp /bin/false blacklist sctp |
CAT II | |||||
| 539 | CCI-000381 | SRG-OS-000095-GPOS-00049 | CCE-84065-2 | The operating system must be configured to disable non-essential capabilities. | Red Hat Enterprise Linux 9 must disable the Transparent Inter Process Communication (TIPC) kernel module. | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). Examples of non-essential capabilities include, but are not limited to, games, software packages, tools, and demonstration software, not related to requirements or providing a wide array of functionality not required for every mission, but which cannot be disabled. |
It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The Transparent Inter Process Communication (TIPC) is a protocol that is specially designed for intra-cluster communication. It can be configured to transmit messages either on UDP or directly across Ethernet. Message delivery is sequence guaranteed, loss free and flow controlled. Disabling TIPC protects the system against exploitation of any flaws in its implementation. |
Applicable - Configurable | Verify the operating system is configured to disable non-essential capabilities. If it does not, this is a finding. | Verify that Red Hat Enterprise Linux 9 disables the ability to load the tipc kernel module with the following command: $ sudo grep -r tipc /etc/modprobe.conf /etc/modprobe.d/* blacklist tipc If the command does not return any output, or the line is commented out, and use of tipc is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. |
To configure the system to prevent the tipc kernel module from being loaded, add the following line to the file /etc/modprobe.d/tipc.conf (or create tipc.conf if it does not exist): install tipc /bin/false blacklist tipc |
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