| Mapping | Rule Title | Description | Rationale |
|---|---|---|---|
| CCE-94601-2 | Record Events that Modify User/Group Information - /etc/passwd |
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/passwd -p wa -k audit_rules_usergroup_modificationIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/passwd -p wa -k audit_rules_usergroup_modification |
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. |
| CCE-94602-0 | Record Events that Modify User/Group Information - /etc/group |
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/group -p wa -k audit_rules_usergroup_modificationIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/group -p wa -k audit_rules_usergroup_modification |
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. |
| CCE-94603-8 | Record Events that Modify User/Group Information - /etc/shadow |
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/shadow -p wa -k audit_rules_usergroup_modificationIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/shadow -p wa -k audit_rules_usergroup_modification |
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. |
| CCE-94604-6 | Record Events that Modify User/Group Information - /etc/security/opasswd |
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modificationIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification |
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. |
| CCE-94605-3 | Ensure auditd Collects Information on the Use of Privileged Commands - ssh-keysign |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/libexec/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/libexec/ssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94606-1 | Ensure auditd Collects Information on the Use of Privileged Commands - passwd |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94607-9 | Ensure auditd Collects Information on the Use of Privileged Commands - gpasswd |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94608-7 | Ensure auditd Collects Information on the Use of Privileged Commands - newgrp |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94609-5 | Ensure auditd Collects Information on the Use of Privileged Commands - chsh |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94610-3 | Ensure auditd Collects Information on the Use of Privileged Commands - unix_chkpwd |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94611-1 | Ensure auditd Collects Information on the Use of Privileged Commands - chage |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94612-9 | Ensure auditd Collects Information on the Use of Privileged Commands - crontab |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94613-7 | Ensure auditd Collects Information on the Use of Privileged Commands - sudoedit |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94614-5 | Ensure auditd Collects Information on the Use of Privileged Commands - chfn |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chfn -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94615-2 | Record Any Attempts to Run ssh-agent |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94616-0 | Ensure auditd Collects Information on the Use of Privileged Commands - kmod |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94617-8 | Record Any Attempts to Run chmod |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chmod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94618-6 | Record Any Attempts to Run setfacl |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94619-4 | Record Any Attempts to Run chacl |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94620-2 | Record Any Attempts to Run chcon |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94621-0 | Record Any Attempts to Run rm |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/rm -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/rm -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
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). |
| CCE-94622-8 | Ensure auditd Collects Information on the Use of Privileged Commands - usermod |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94623-6 | Ensure auditd Collects Information on the Use of Privileged Commands - pam_timestamp_check |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94624-4 | Ensure auditd Collects Information on the Use of Privileged Commands - su |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94625-1 | Ensure auditd Collects Information on the Use of Privileged Commands - sudo |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94626-9 | Enable SSH Warning Banner |
To enable the warning banner and ensure it is consistent
across the system, add or correct the following line in
/etc/ssh/sshd_config:
Banner /etc/issueAnother section contains information on how to create an appropriate system-wide warning banner. |
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. |
| CCE-94627-7 | Set SSH Daemon LogLevel to VERBOSE |
The VERBOSE parameter configures the SSH daemon to record login and logout activity.
To specify the log level in
SSH, add or correct the following line in
/etc/ssh/sshd_config:
LogLevel VERBOSE |
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. |
| CCE-94628-5 | Record Attempts to Alter Logon and Logout Events - tallylog |
The audit system already collects login information for all users
and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/tallylog -p wa -k loginsIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /var/log/tallylog -p wa -k logins |
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion. |
| CCE-94629-3 | Record Attempts to Alter Logon and Logout Events - lastlog |
The audit system already collects login information for all users
and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/lastlog -p wa -k loginsIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /var/log/lastlog -p wa -k logins |
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion. |
| CCE-94630-1 | Check that vlock is installed to allow session locking |
The SUSE Linux Enterprise Micro 6 operating system must have vlock installed to allow for session locking.
The kbd package can be installed with the following command:
$ sudo zypper install kbd |
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 must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system. |
| CCE-94631-9 | Enable auditd Service |
The auditd service is an essential userspace component of
the Linux Auditing System, as it is responsible for writing audit records to
disk.
The auditd service can be enabled with the following command:
$ sudo systemctl enable auditd.service |
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. |
| CCE-94632-7 | Record Events that Modify the System's Discretionary Access Controls - fremovexattr |
At a minimum, the audit system should collect file permission
changes for all users and root.
If the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following line to a file with suffix .rules in the directory /etc/audit/rules.d: -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod If the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod If the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file: -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod If the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod |
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. |
| CCE-94633-5 | Record Events that Modify the System's Discretionary Access Controls - lchown |
At a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_modIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file: -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod |
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. |
| CCE-94634-3 | Record Events that Modify the System's Discretionary Access Controls - fchmod |
At a minimum, the audit system should collect file permission
changes for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_modIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file: -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod |
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. |
| CCE-94635-0 | Ensure auditd Collects Information on Exporting to Media (successful) |
At a minimum, the audit system should collect media exportation
events for all users and root. If the auditd daemon is configured to
use the augenrules program to read audit rules during daemon startup
(the default), add the following line to a file with suffix .rules in
the directory /etc/audit/rules.d, setting ARCH to either b32 for
32-bit system, or having two lines for both b32 and b64 in case your
system is 64-bit:
-a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=exportIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit: -a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export |
The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss. |
| CCE-94636-8 | Record Events that Modify the System's Discretionary Access Controls - umount2 |
At a minimum, the audit system should collect file system umount2
changes. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following line to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_modIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following line to /etc/audit/audit.rules file: -a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_modIf the system is 64 bit then also add the following line: -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -F key=perm_mod |
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. |
| CCE-94637-6 | Set Password Strength Minimum Uppercase Characters | The pam_cracklib module's ucredit= parameter controls requirements for usage of uppercase letters in a password. When set to a negative number, any password will be required to contain that many uppercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each uppercase character. Add ucredit=-1 after pam_cracklib.so to require use of an upper case character in passwords. | Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space. |
| CCE-94638-4 | Set Password Strength Minimum Lowercase Characters | The pam_cracklib module's lcredit= parameter controls requirements for usage of lowercase letters in a password. When set to a negative number, any password will be required to contain that many lowercase characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each lowercase character. Add lcredit=-1 after pam_cracklib.so to require use of a lowercase character in passwords. | Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space. |
| CCE-94639-2 | Set Password Strength Minimum Digit Characters | The pam_cracklib module's dcredit parameter controls requirements for usage of digits in a password. When set to a negative number, any password will be required to contain that many digits. When set to a positive number, pam_cracklib will grant +1 additional length credit for each digit. Add dcredit=-1 after pam_cracklib.so to require use of a digit in passwords. | Requiring digits makes password guessing attacks more difficult by ensuring a larger search space. |
| CCE-94640-0 | Set Password Strength Minimum Different Characters | The pam_cracklib module's difok parameter controls requirements for usage of different characters during a password change. 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. Make sure the difok parameter for the pam_cracklib module is configured to greater than or equal to 8. | 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. |
| CCE-94641-8 | Limit Password Reuse |
Do not allow users to reuse recent passwords. This can be
accomplished by using the remember option for the
pam_pwhistory PAM modules.
In the file /etc/pam.d/common-password, make sure the parameters remember and use_authtok are present, and that the value for the remember parameter is 5 or greater. For example: password requisite pam_pwhistory.so ...existing_options... remember=5 use_authtokThe profile requirement is 5 passwords. |
Preventing reuse of previous passwords helps ensure that a compromised password is not reused by a user. |
| CCE-94642-6 | Set Password Minimum Length | The pam_cracklib module's minlen parameter controls requirements for minimum characters required in a password. Add minlen=15 to set minimum password length requirements. | 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. |
| CCE-94643-4 | Uninstall telnet-server Package |
The telnet-server package can be removed with the following command:
$ sudo zypper remove telnet-server |
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
insecure. 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 the telnet service's accidental (or intentional) activation. |
| CCE-94644-2 | Limit the Number of Concurrent Login Sessions Allowed Per User |
Limiting the number of allowed users and sessions per user can limit risks related to Denial of
Service attacks. This addresses concurrent sessions for a single account and does not address
concurrent sessions by a single user via multiple accounts. To set the number of concurrent
sessions per user add the following line in /etc/security/limits.conf or
a file under /etc/security/limits.d/:
* hard maxlogins 1 |
Limiting simultaneous user logins can insulate the system from denial of service problems caused by excessive logins. Automated login processes operating improperly or maliciously may result in an exceptional number of simultaneous login sessions. |
| CCE-94645-9 | Set Interactive Session Timeout |
Setting the TMOUT option in /etc/profile ensures that
all user sessions will terminate based on inactivity. A value of 0 (zero)
disables the automatic logout feature and is therefore not a compliant setting.
The value of TMOUT should be a positive integer, exported, and read only.
The TMOUT
setting in /etc/profile.d/autologout.sh should read as follows:
TMOUT=600readonly TMOUT export TMOUT |
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. |
| CCE-94646-7 | Use Only FIPS 140-2 Validated Ciphers |
Limit the ciphers to those algorithms which are FIPS-approved.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved ciphers:
Ciphers aes256-ctr,aes192-ctr,aes128-ctrThis rule ensures that there are configured ciphers mentioned above (or their subset), keeping the given order of algorithms. |
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 system data may be compromised.
Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets industry and government requirements. For government systems, this allows Security Levels 1, 2, 3, or 4 for use on SUSE Linux Enterprise Micro 6. |
| CCE-94647-5 | Use Only FIPS 140-2 Validated Ciphers |
Limit the ciphers to those algorithms which are FIPS-approved.
Counter (CTR) mode is also preferred over cipher-block chaining (CBC) mode.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved ciphers:
Ciphers aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbcThe man page sshd_config(5) contains a list of supported ciphers. The rule is parametrized to use the following ciphers: aes128-ctr,aes192-ctr,aes256-ctr,aes128-cbc,3des-cbc,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se.
|
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 system data may be compromised.
Operating systems utilizing encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-2 is the current standard for validating that mechanisms used to access cryptographic modules utilize authentication that meets industry and government requirements. For government systems, this allows Security Levels 1, 2, 3, or 4 for use on SUSE Linux Enterprise Micro 6. |
| CCE-94648-3 | Ensure auditd Collects System Administrator Actions |
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /etc/sudoers -p wa -k actionsIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/sudoers -p wa -k actionsIf the auditd daemon is configured to use the augenrules program to read audit rules during daemon startup (the default), add the following lines to a file with suffix .rules in the directory /etc/audit/rules.d: -w /etc/sudoers.d/ -p wa -k actionsIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /etc/sudoers.d/ -p wa -k actions |
The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes. |
| CCE-94649-1 | Record Unsuccessful Access Attempts to Files - open |
At a minimum, the audit system should collect unauthorized file
accesses for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d:
-a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=accessIf the system is 64 bit then also add the following lines: -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=accessIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules file: -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=accessIf the system is 64 bit then also add the following lines: -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access |
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. |
| CCE-94650-9 | Ensure auditd Collects Information on the Use of Privileged Commands - insmod |
At a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/insmod -p x -k modules |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94651-7 | Ensure auditd Collects Information on the Use of Privileged Commands - rmmod |
At a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/rmmod -p x -k modules |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94652-5 | Ensure auditd Collects Information on the Use of Privileged Commands - modprobe |
At a minimum, the audit system should collect the execution of
privileged commands for all users and root. If the auditd daemon is
configured to use the augenrules program to read audit rules during
daemon startup (the default), add a line of the following form to a file with
suffix .rules in the directory /etc/audit/rules.d:
-w /sbin/modprobe -p x -k modulesIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -w /sbin/modprobe -p x -k modules |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-94653-3 | Ensure auditd Collects Information on Kernel Module Unloading - delete_module |
To capture kernel module loading and unloading events, use the following line, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S delete_module -F key=modulesPlace to add the line depends on a way auditd daemon is configured. If it is configured to use the augenrules program (the default), add the line to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility, add the line to file /etc/audit/audit.rules. |
The removal 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. |
| CCE-94654-1 | Ensure auditd Collects Information on Kernel Module Loading and Unloading - finit_module |
To capture kernel module loading and unloading events, use the following line, setting ARCH to
either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
-a always,exit -F arch=ARCH -S finit_module -F key=modulesPlace to add the line depends on a way auditd daemon is configured. If it is configured to use the augenrules program (the default), add the line to a file with suffix .rules in the directory /etc/audit/rules.d. If the auditd daemon is configured to use the auditctl utility, add the line to file /etc/audit/audit.rules. |
The addition/removal 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. |
| CCE-94655-8 | Configure auditd mail_acct Action on Low Disk Space |
The auditd service can be configured to send email to
a designated account in certain situations. Add or correct the following line
in /etc/audit/auditd.conf to ensure that administrators are notified
via email for those situations:
action_mail_acct = root |
Email sent to the root account is typically aliased to the administrators of the system, who can take appropriate action. |
| CCE-94656-6 | Configure System to Forward All Mail For The Root Account |
Make sure that mails delivered to root user are forwarded to a monitored
email address. Make sure that the address
change_me@localhost is a valid email address
reachable from the system in question. Use the following command to
configure the alias:
$ sudo echo "root: change_me@localhost" >> /etc/aliases $ sudo newaliases |
A number of system services utilize email messages sent to the root user to notify system administrators of active or impending issues. These messages must be forwarded to at least one monitored email address. |
| CCE-94657-4 | Configure auditd Disk Full Action when Disk Space Is Full |
The auditd service can be configured to take an action
when disk space is running low but prior to running out of space completely.
Edit the file /etc/audit/auditd.conf. Add or modify the following line,
substituting ACTION appropriately:
disk_full_action = ACTIONSet this value to single to cause the system to switch to single-user mode for corrective action. Acceptable values also include syslog, exec, single, and halt For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the auditd.conf man page. |
Taking appropriate action in case of a filled audit storage volume will minimize the possibility of losing audit records. |
| CCE-94658-2 | Enable Smart Card Logins in PAM |
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).
Check that the pam_pkcs11.so option is configured in the
etc/pam.d/common-auth file with the following command:
# grep pam_pkcs11.so /etc/pam.d/common-auth auth sufficient pam_pkcs11.soFor general information about enabling smart card authentication, consult the documentation at: |
Smart card login provides two-factor authentication stronger than that provided by a username and password combination. Smart cards leverage PKI (public key infrastructure) in order to provide and verify credentials. Using an authentication device, such as a 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 or similar secure authentication devices issued by an organization or identity provider. |
| CCE-94659-0 | Set PAM Password Hashing Algorithm - system-auth |
The PAM system service can be configured to only store encrypted representations of passwords.
In "/etc/pam.d/common-password", the password section of the file controls which
PAM modules to execute during a password change.
Set the pam_unix.so module in the password section to include the option
sha512 and no other hashing
algorithms as shown below:
password required pam_unix.so sha512 other arguments... This will help ensure that new passwords for local users will be stored using the sha512 algorithm. |
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 in /etc/libuser.conf ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult. |
| CCE-94660-8 | Set Password Hashing Rounds in /usr/etc/login.defs |
In /usr/etc/login.defs, ensure SHA_CRYPT_MIN_ROUNDS and
SHA_CRYPT_MAX_ROUNDS has the minimum value of 5000.
For example:
SHA_CRYPT_MIN_ROUNDS 5000 SHA_CRYPT_MAX_ROUNDS 5000Notice that if neither are set, they already have the default value of 5000. If either is set, they must have the minimum value of 5000. |
Passwords need to be protected at all times, and hashing is the standard
method for protecting passwords. If passwords are not hashed, they can
be plainly read (i.e., clear text) and easily compromised. Passwords
that are hashed 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. |
| CCE-94661-6 | Set Existing Passwords Minimum Age |
Configure non-compliant accounts to enforce a 24 hours/1 day minimum password
lifetime by running the following command:
$ sudo chage -m 1 USER |
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. |
| CCE-94662-4 | Set Existing Passwords Maximum Age |
Configure non-compliant accounts to enforce a 60-day maximum password lifetime
restriction by running the following command:
$ sudo chage -M 60 USER |
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. |
| CCE-94663-2 | Verify Permissions and Ownership of Old Passwords File |
To properly set the owner of /etc/security/opasswd, run the command:
$ sudo chown root /etc/security/opasswdTo properly set the group owner of /etc/security/opasswd, run the command:
$ sudo chgrp root /etc/security/opasswdTo properly set the permissions of /etc/security/opasswd, run the command: $ sudo chmod 0600 /etc/security/opasswd |
The /etc/security/opasswd file stores old passwords to prevent password reuse. Protection of this file is critical for system security. |
| CCE-94664-0 | Set Boot Loader Password in grub2 |
The grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password by running the following command: # grub2-mkpasswd-pbkdf2When prompted, enter the password that was selected. Using the hash from the output, modify the /etc/grub.d/40_custom file with the following content: set superusers="boot" password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongStringNOTE: the bootloader superuser account and password MUST differ from the root account and password. Once the superuser password has been added, update the grub.cfg file by running: grub2-mkconfig -o /boot/grub2/grub.cfg |
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. |
| CCE-94665-7 | Modify the System Login Banner |
To configure the system login banner edit /etc/issue. Replace the
default text with a message compliant with the local site policy or a legal
disclaimer.
The DoD required text is either:
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. OR: I've read & consent 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. |
| CCE-94666-5 | Verify that Local Logs of the audit Daemon are not World-Readable |
Files containing sensitive information should be protected by restrictive
permissions. Most of the time, there is no need that these files need to be
read by any non-root user.
Check that "permissions.local" file contains the correct permissions rules with the following command:
# grep -i audit /etc/permissions.local /var/log/audit/ root:root 600 /var/log/audit/audit.log root:root 600 /etc/audit/audit.rules root:root 640 /etc/audit/rules.d/audit.rules root:root 640 |
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. |
| CCE-94667-3 | Configure Smart Card Certificate Authority Validation |
Configure the operating system to do certificate status checking for PKI
authentication. Modify all of the cert_policy lines in
/etc/pam_pkcs11/pam_pkcs11.conf to include ca like so:
cert_policy = ca, ocsp_on, signature; |
Using an authentication device, such as a 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 or similar secure authentication devices issued by an organization or identity provider. |
| CCE-94668-1 | OpenSSH Service Must Use Passcode for Their Private Keys |
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/fileIf the contents of the key are displayed, without asking a passphrase this is a finding. |
If an unauthorized user obtains access to a private key without a passcode, that user would have unauthorized access to any system where the associated public key has been installed. |
| CCE-94669-9 | Set Password Minimum Age |
To specify password minimum age for new accounts,
edit the file /usr/etc/login.defs
and add or correct the following line:
PASS_MIN_DAYS 7A value of 1 day is considered sufficient for many environments. The profile requirement is 7. |
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. |
| CCE-94670-7 | Set Password Maximum Age |
To specify password maximum age for new accounts,
edit the file /usr/etc/login.defs
and add or correct the following line:
PASS_MAX_DAYS 60The profile requirement is 60. |
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. |
| CCE-94671-5 | Set the UEFI Boot Loader Password |
The grub2 boot loader should have a superuser account and password
protection enabled to protect boot-time settings.
Since plaintext passwords are a security risk, generate a hash for the password by running the following command: # grub2-mkpasswd-pbkdf2When prompted, enter the password that was selected. Using the hash from the output, modify the /etc/grub.d/40_custom file with the following content: set superusers="boot" password_pbkdf2 boot grub.pbkdf2.sha512.VeryLongStringNOTE: the bootloader superuser account and password MUST differ from the root account and password. Once the superuser password has been added, update the grub.cfg file by running: grub2-mkconfig -o /boot/grub2/grub.cfg |
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. |
| CCE-94672-3 | Verify firewalld Enabled |
The firewalld service can be enabled with the following command:
$ sudo systemctl enable firewalld.service |
Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols. |
| CCE-94673-1 | Ensure All Accounts on the System Have Unique User IDs | Change user IDs (UIDs), or delete accounts, so each has a unique name. | To assure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. |
| CCE-94674-9 | Disable SSH Root Login |
The root user should never be allowed to login to a
system directly over a network.
To disable root login via SSH, add or correct the following line in
/etc/ssh/sshd_config:
PermitRootLogin no |
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. |
| CCE-94675-6 | Set Account Expiration Following Inactivity |
To specify the number of days after a password expires (which
signifies inactivity) until an account is permanently disabled, add or correct
the following line in /etc/default/useradd:
INACTIVE=35If a password is currently on the verge of expiration, then 35 day(s) remain(s) until the account is automatically disabled. However, if the password will not expire for another 60 days, then 60 days plus 35 day(s) could elapse until the account would be automatically disabled. See the useradd man page for more information. |
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. |
| CCE-94676-4 | Verify All Account Password Hashes are Shadowed with SHA512 |
Verify the operating system requires the shadow password suite
configuration be set to encrypt interactive user passwords using a strong
cryptographic hash.
Check 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. |
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. |
| CCE-94677-2 | Never Automatically Remove or Disable Emergency Administrator Accounts |
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.
Check to see if an emergency administrator account password or account expires with the following command:
# sudo chage -l [Emergency_Administrator] Password expires:neverIf Password expires or Account expires is set to anything other than never, this is a finding. |
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 the SUSE operating system can be integrated with enterprise-level authentication/access mechanisms that meet or exceed access control policy requirements. |
| CCE-94678-0 | Assign Expiration Date to Temporary Accounts |
Temporary accounts are established as part of normal account activation
procedures when there is a need for short-term accounts. In the event
temporary accounts are required, configure the system to
terminate them after a documented time period. For every temporary account, run the following command to set an expiration date on
it, substituting USER and YYYY-MM-DD
appropriately:
$ sudo chage -E YYYY-MM-DD USERYYYY-MM-DD indicates the documented expiration date for the account. For U.S. Government systems, the operating system must be configured to automatically terminate these types of accounts after a period of 72 hours. |
If temporary user accounts remain active when no longer needed or for
an excessive period, these accounts may be used to gain unauthorized access.
To mitigate this risk, automated termination of all temporary accounts
must be set upon account creation.
|
| CCE-94679-8 | Use Only FIPS 140-2 Validated MACs |
Limit the MACs to those hash algorithms which are FIPS-approved.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved MACs:
MACs hmac-sha2-512,hmac-sha2-256This rule ensures that there are configured MACs mentioned above (or their subset), keeping the given order of algorithms. |
FIPS-approved cryptographic hash functions are required to be used. The only SSHv2 hash algorithms meeting this requirement is SHA2. |
| CCE-94680-6 | Use Only FIPS 140-2 Validated MACs |
Limit the MACs to those hash algorithms which are FIPS-approved.
The following line in /etc/ssh/sshd_config
demonstrates use of FIPS-approved MACs:
MACs hmac-sha2-512,hmac-sha2-256The man page sshd_config(5) contains a list of supported MACs. The rule is parametrized to use the following MACs: hmac-sha2-512,hmac-sha2-256,hmac-sha1,hmac-sha1-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com.
|
FIPS-approved cryptographic hash functions are required to be used. The only SSHv2 hash algorithms meeting this requirement is SHA2. |
| CCE-94681-4 | Set SSH Client Alive Interval |
SSH allows administrators to set a network responsiveness timeout interval.
After this interval has passed, the unresponsive client will be automatically logged out.
To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows: ClientAliveInterval 300 The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600. If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle. |
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 let unattended. |
| CCE-94682-2 | Verify that All World-Writable Directories Have Sticky Bits Set |
When the so-called 'sticky bit' is set on a directory, only the owner of a given file may
remove that file from the directory. Without the sticky bit, any user with write access to a
directory may remove any file in the directory. Setting the sticky bit prevents users from
removing each other's files. In cases where there is no reason for a directory to be
world-writable, a better solution is to remove that permission rather than to set the sticky
bit. However, if a directory is used by a particular application, consult that application's
documentation instead of blindly changing modes.
To set the sticky bit on a world-writable directory DIR, run the following command: $ sudo chmod +t DIR |
Failing to set the sticky bit on public directories allows unauthorized users to delete files
in the directory structure.
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, by users for temporary file storage (such as /tmp), and for directories requiring global read/write access. |
| CCE-94683-0 | Restrict Access to Kernel Message Buffer |
To set the runtime status of the kernel.dmesg_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.dmesg_restrict=1To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.dmesg_restrict = 1 |
Unprivileged access to the kernel syslog can expose sensitive kernel address information. |
| CCE-94684-8 | Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces |
To set the runtime status of the net.ipv4.tcp_syncookies kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.tcp_syncookies=1To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.tcp_syncookies = 1 |
A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests. |
| CCE-94685-5 | Set SSH Client Alive Count Max | The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. For SSH earlier than v8.2, a ClientAliveCountMax value of 0 causes a timeout precisely when the ClientAliveInterval is set. Starting with v8.2, a value of 0 disables the timeout functionality completely. If the option is set to a number greater than 0, then the session will be disconnected after ClientAliveInterval * ClientAliveCountMax seconds without receiving a keep alive message. | This ensures a user login will be terminated as soon as the ClientAliveInterval is reached. |
| CCE-94686-3 | Encrypt Partitions |
SUSE Linux Enterprise Micro 6 natively supports partition encryption through the
Linux Unified Key Setup-on-disk-format (LUKS) technology. The easiest way to
encrypt a partition is during installation time.
For manual installations, select the Encrypt checkbox during partition creation to encrypt the partition. When this option is selected the system will prompt for a passphrase to use in decrypting the partition. The passphrase will subsequently need to be entered manually every time the system boots. Detailed information on encrypting partitions using LUKS or LUKS ciphers can be found on the SUSE Linux Enterprise Micro 6 Documentation web site: https://documentation.suse.com/sle-micro/6.0/html/Micro-deployment-raw-images/index.html#deployment-jeos-firstboot . |
The risk of a system's physical compromise, particularly mobile systems such as laptops, places its data at risk of compromise. Encrypting this data mitigates the risk of its loss if the system is lost. |
| CCE-94687-1 | Verify permissions of log files | 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. | The SUSE Linux Enterprise Micro 6 must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries. |
| CCE-94688-9 | Use Only FIPS 140-2 Validated Key Exchange Algorithms |
Limit the key exchange algorithms to those which are FIPS-approved.
Add or modify the following line in /etc/ssh/sshd_config
KexAlgorithms ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256This rule ensures that only the key exchange algorithms mentioned above (or their subset) are configured for use, keeping the given order of algorithms. |
FIPS-approved key exchange algorithms are required to be used. The system will attempt to use the first algorithm presented by the client that matches the server list. Listing the values "strongest to weakest" is a method to ensure the use of the strongest algorithm available to secure the SSH connection. |
| CCE-94689-7 | Verify Permissions of Local Logs of audit Tools |
The SUSE operating system audit tools must have the proper permissions
configured to protect against unauthorized access.
Check that "permissions.local" file contains the correct permissions rules
with the following command:
grep "^/usr/sbin/au" /etc/permissions.local /usr/sbin/audispd root:root 0750 /usr/sbin/auditctl root:root 0750 /usr/sbin/auditd root:root 0750 /usr/sbin/ausearch root:root 0755 /usr/sbin/aureport root:root 0755 /usr/sbin/autrace root:root 0750 /usr/sbin/augenrules root:root 0750Audit 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. SUSE 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 enjoys to make access decisions regarding the access to audit tools. |
| CCE-94690-5 | Verify that Shared Library Files Have Restrictive Permissions |
System-wide shared library files, which are linked to executables
during process load time or run time, are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64Kernel modules, which can be added to the kernel during runtime, are stored in /lib/modules. All files in these directories should not be group-writable or world-writable. If any file in these directories is found to be group-writable or world-writable, correct its permission with the following command: $ sudo chmod go-w FILE |
Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Restrictive permissions are necessary to protect the integrity of the system. |
| CCE-94691-3 | Verify that Shared Library Directories Have Restrictive Permissions |
System-wide shared library directories, which contain are linked to executables
during process load time or run time, are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64Kernel modules, which can be added to the kernel during runtime, are stored in /lib/modules. All sub-directories in these directories should not be group-writable or world-writable. If any file in these directories is found to be group-writable or world-writable, correct its permission with the following command: $ sudo chmod go-w DIR |
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 must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
| CCE-94692-1 | Verify that Shared Library Files Have Root Ownership |
System-wide shared library files, which are linked to executables
during process load time or run time, are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64Kernel modules, which can be added to the kernel during runtime, are also stored in /lib/modules. All files in these directories should be owned by the root user. If the directory, or any file in these directories, is found to be owned by a user other than root correct its ownership with the following command: $ sudo chown root FILE |
Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Proper ownership is necessary to protect the integrity of the system. |
| CCE-94693-9 | Verify that Shared Library Directories Have Root Ownership |
System-wide shared library files, which are linked to executables
during process load time or run time, are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64Kernel modules, which can be added to the kernel during runtime, are also stored in /lib/modules. All files in these directories should be owned by the root user. If the directories, is found to be owned by a user other than root correct its ownership with the following command: $ sudo chown root DIR |
Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Proper ownership of library directories is necessary to protect the integrity of the system. |
| CCE-94694-7 | Verify the system-wide library files in directories "/lib", "/lib64", "/usr/lib/" and "/usr/lib64" are group-owned by root. |
System-wide library files are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64All system-wide shared library files should be protected from unauthorised access. If any of these files is not group-owned by root, correct its group-owner with the following command: $ sudo chgrp root FILE |
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 must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
| CCE-94695-4 | Verify that Shared Library Directories Have Root Group Ownership |
System-wide shared library files, which are linked to executables
during process load time or run time, are stored in the following directories
by default:
/lib /lib64 /usr/lib /usr/lib64Kernel modules, which can be added to the kernel during runtime, are also stored in /lib/modules. All files in these directories should be group-owned by the root user. If the directories, is found to be owned by a user other than root correct its ownership with the following command: $ sudo chgrp root DIR |
Files from shared library directories are loaded into the address space of processes (including privileged ones) or of the kernel itself at runtime. Proper ownership of library directories is necessary to protect the integrity of the system. |
| CCE-94696-2 | Verify that System Executables Have Restrictive Permissions |
System executables are stored in the following directories by default:
/bin /sbin /usr/bin /usr/libexec /usr/local/bin /usr/local/sbin /usr/sbinAll files in these directories should not be group-writable or world-writable. If any file FILE in these directories is found to be group-writable or world-writable, correct its permission with the following command: $ sudo chmod go-w FILE |
System binaries are executed by privileged users, as well as system services, and restrictive permissions are necessary to ensure execution of these programs cannot be co-opted. |
| CCE-94697-0 | Verify that System Executables Have Root Ownership |
System executables are stored in the following directories by default:
/bin /sbin /usr/bin /usr/libexec /usr/local/bin /usr/local/sbin /usr/sbinAll files in these directories should be owned by the root user. If any file FILE in these directories is found to be owned by a user other than root, correct its ownership with the following command: $ sudo chown root FILE |
System binaries are executed by privileged users as well as system services, and restrictive permissions are necessary to ensure that their execution of these programs cannot be co-opted. |
| CCE-94698-8 | Verify that system commands directories have root ownership |
System commands are stored in the following directories by default:
/bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbinAll these directories should be owned by the root user. If any system command directory is not owned by a user other than root correct its ownership with the following command: $ sudo chown root DIR |
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 must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
| CCE-94699-6 | Verify that system commands files are group owned by root or a system account |
System commands files are stored in the following directories by default:
/bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbinAll files in these directories should be owned by the root group, or a system account. If the directory, or any file in these directories, is found to be owned by a group other than root or a a system account correct its ownership with the following command: $ sudo chgrp root FILE |
If the operating system allows 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 must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
| CCE-94700-2 | Verify that system commands directories have root as a group owner |
System commands are stored in the following directories:
by default:
/bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbinAll these directories should have root user as a group owner. If any system command directory is not group owned by a user other than root correct its ownership with the following command: $ sudo chgrp root DIR |
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 must be allowed to obtain access to information system components for purposes of initiating changes, including upgrades and modifications. |
| CCE-94701-0 | Set Password Strength Minimum Special Characters | The pam_cracklib module's ocredit= parameter controls requirements for usage of special (or ``other'') characters in a password. When set to a negative number, any password will be required to contain that many special characters. When set to a positive number, pam_cracklib will grant +1 additional length credit for each special character. Make sure the ocredit parameter for the pam_cracklib module is set to less than or equal to -1. For example, ocredit=-1. | Requiring a minimum number of special characters makes password guessing attacks more difficult by ensuring a larger search space. |
| CCE-94702-8 | Configure AIDE to Verify the Audit Tools | The operating system file integrity tool must be configured to protect the integrity of the 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 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. |
| CCE-94703-6 | Deactivate Wireless Network Interfaces |
Deactivating wireless network interfaces should prevent normal usage of the wireless
capability.
Configure the system to disable all wireless network interfaces with the following command: $ sudo nmcli radio all off |
The use of wireless networking can introduce many different attack vectors into the organization's network. Common attack vectors such as malicious association and ad hoc networks will allow an attacker to spoof a wireless access point (AP), allowing validated systems to connect to the malicious AP and enabling the attacker to monitor and record network traffic. These malicious APs can also serve to create a man-in-the-middle attack or be used to create a denial of service to valid network resources. |
| CCE-94704-4 | Record Events When Privileged Executables Are Run |
Verify the system generates an audit record when privileged functions are executed.
If audit is using the "auditctl" tool to load the rules, run the following command:
$ sudo grep execve /etc/audit/audit.rulesIf audit is using the "augenrules" tool to load the rules, run the following command: $ sudo grep -r execve /etc/audit/rules.d -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k setuid -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k setgid -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k setgidIf both the "b32" and "b64" audit rules for "SUID" files are not defined, this is a finding. If both the "b32" and "b64" audit rules for "SGID" files are not defined, this is a finding. |
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. |
| CCE-94705-1 | Ensure the audit Subsystem is Installed | The audit package should be installed. | The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy. |
| CCE-94706-9 | Configure a Sufficiently Large Partition for Audit Logs |
The SUSE Linux Enterprise Micro 6 operating system must allocate audit record storage
capacity to store at least one weeks worth of audit records when audit
records are not immediately sent to a central audit record storage
facility.
The partition size needed to capture a week's worth of audit records is
based on the activity level of the system and the total storage capacity
available.
In normal circumstances, 10.0 GB of storage space for audit
records will 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.logCheck the size of the partition that audit records are written to with the following command: $ sudo df -h /var/log/audit/ /dev/sda2 24G 10.4G 13.6G 43% /var/log/audit |
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. |
| CCE-94707-7 | Ensure the default plugins for the audit dispatcher are Installed | The audit-audispd-plugins package should 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. |
| CCE-94708-5 | Encrypt Audit Records Sent With audispd Plugin |
Configure the operating system to encrypt the transfer of off-loaded audit
records onto a different system or media from the system being audited.
Uncomment the enable_krb5 option in /etc/audit/audisp-remote.conf, and set it with the following line: enable_krb5 = yes |
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. |
| CCE-94709-3 | Configure audispd Plugin To Send Logs To Remote Server |
Configure the audispd plugin to off-load audit records onto a different
system or media from the system being audited.
Set the remote_server option in /etc/audit/audisp-remote.confwith an IP address or hostname of the system that the audispd plugin should send audit records to. For example remote_server = logcollector |
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. |
| CCE-94710-1 | Configure auditd space_left on Low Disk Space |
The auditd service can be configured to take an action
when disk space is running low but prior to running out of space completely.
Edit the file /etc/audit/auditd.conf. Add or modify the following line,
substituting PERCENTAGE appropriately:
space_left = PERCENTAGE%Set this value to at least 25 to cause the system to notify the user of an issue. |
Notifying administrators of an impending disk space problem may allow them to take corrective action prior to any disruption. |
| CCE-94711-9 | Configure auditd space_left Action on Low Disk Space |
The auditd service can be configured to take an action
when disk space starts to run low.
Edit the file /etc/audit/auditd.conf. Modify the following line,
substituting ACTION appropriately:
space_left_action = ACTIONPossible values for ACTION are described in the auditd.conf man page. These include:
|
Notifying administrators of an impending disk space problem may allow them to take corrective action prior to any disruption. |
| CCE-94712-7 | Install AIDE |
The aide package can be installed with the following command:
$ sudo zypper install aide |
The AIDE package must be installed if it is to be available for integrity checking. |
| CCE-94713-5 | Build and Test AIDE Database |
Run the following command to generate a new database:
$ sudo /usr/bin/aide --initBy default, the database will be written to the file /var/lib/aide/aide.db.new. Storing the database, the configuration file /etc/aide.conf, and the binary /usr/bin/aide (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows: $ sudo cp /var/lib/aide/aide.db.new /var/lib/aide/aide.dbTo initiate a manual check, run the following command: $ sudo /usr/bin/aide --checkIf this check produces any unexpected output, investigate. |
For AIDE to be effective, an initial database of "known-good" information about files must be captured and it should be able to be verified against the installed files. |
| CCE-94714-3 | Configure Systemd Timer Execution of AIDE |
At a minimum, AIDE should be configured to run a weekly scan.
To implement a systemd service and a timer unit to run the service periodically:
For example, if a systemd timer is expected to be started every day at 5AM
OnCalendar=*-*-* 05:00:0 [Timer]section in the timer unit and a Unit section starting the AIDE check service unit should be referred. |
AIDE provides a means to check if unauthorized changes are made to the system. AIDE itself does not setup a periodic execution, so in order to detect unauthorized changes a systemd service to run the check and a systemd timer to take care of periodical execution of that systemd service should be defined. |
| CCE-94715-0 | Ensure gpgcheck Enabled In Main zypper Configuration |
The gpgcheck option controls whether
RPM packages' signatures are always checked prior to installation.
To configure zypper to check package signatures before installing
them, ensure the following line appears in /etc/zypp/zypp.conf in
the [main] section:
gpgcheck=1 |
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. Certificates used to verify the software must be from an approved Certificate Authority (CA). |
| CCE-94716-8 | Ensure Users Re-Authenticate for Privilege Escalation - sudo | The sudo NOPASSWD and !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that NOPASSWD and/or !authenticate do not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/." |
Without re-authentication, 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 re-authenticate. |
| CCE-94717-6 | Ensure Users Re-Authenticate for Privilege Escalation - sudo NOPASSWD | The sudo NOPASSWD tag, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that the NOPASSWD tag does not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/. |
Without re-authentication, 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 re-authenticate. |
| CCE-94718-4 | Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticate | The sudo !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that the !authenticate option does not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/. |
Without re-authentication, 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 re-authenticate. |
| CCE-94719-2 | Require Re-Authentication When Using the sudo Command | The sudo timestamp_timeout tag sets the amount of time sudo password prompt waits. The default timestamp_timeout value is 5 minutes. The timestamp_timeout should be configured by making sure that the timestamp_timeout tag exists in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/. 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 re-authenticate for privileged actions until the user's session is terminated. |
Without re-authentication, 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 re-authenticate. |
| CCE-94720-0 | Install Smart Card Packages For Multifactor Authentication |
Configure the operating system to implement multifactor authentication by
installing the required package with the following command:
The pam_pkcs11 package can be installed with the following command:
$ sudo zypper install pam_pkcs11The mozilla-nss package can be installed with the following command:
$ sudo zypper install mozilla-nssThe mozilla-nss-tools package can be installed with the following command:
$ sudo zypper install mozilla-nss-toolsThe pcsc-ccid package can be installed with the following command:
$ sudo zypper install pcsc-ccidThe pcsc-lite package can be installed with the following command:
$ sudo zypper install pcsc-liteThe pcsc-tools package can be installed with the following command:
$ sudo zypper install pcsc-toolsThe opensc package can be installed with the following command:
$ sudo zypper install openscThe coolkey package can be installed with the following command:
$ sudo zypper install coolkey |
Using an authentication device, such as a 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 or similar secure authentication devices issued by an organization or identity provider. |
| CCE-94721-8 | Configure Smart Card Certificate Status Checking |
Configure the operating system to do certificate status checking for PKI
authentication. Modify all of the cert_policy lines in
/etc/pam_pkcs11/pam_pkcs11.conf to include ocsp_on like so:
cert_policy = ca, ocsp_on, signature; |
Using an authentication device, such as a 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 or similar secure authentication devices issued by an organization or identity provider. |
| CCE-94722-6 | Disable Modprobe Loading of USB Storage Driver |
To prevent USB storage devices from being used, configure the kernel module loading system
to prevent automatic loading of the USB storage driver.
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:
install usb-storage /bin/falseThis entry will cause a non-zero return value during a usb-storage module installation
and additionally convey the meaning of the entry to the user in form of an error message.
If you would like to omit a non-zero return value and an error message, you may want to add a different line instead
(both /bin/true and /bin/false are allowed by OVAL and will be accepted by the scan):
install usb-storage /bin/trueThis will prevent the modprobe program from loading the usb-storage module, but will not prevent an administrator (or another program) from using the insmod program to load the module manually. |
USB storage devices such as thumb drives can be used to introduce malicious software. |
| CCE-94723-4 | Configure SSSD's Memory Cache to Expire |
SSSD's memory cache should be configured to set to expire records after
300 seconds.
To configure SSSD to expire memory cache, set memcache_timeout to
300 under the
[nss] section in /etc/sssd/sssd.conf.
For example:
[nss] memcache_timeout = 300 |
If cached authentication information is out-of-date, the validity of the authentication information may be questionable. |
| CCE-94724-2 | Configure SSSD to Expire Offline Credentials |
SSSD should be configured to expire offline credentials after 1 day.
To configure SSSD to expire offline credentials, set
offline_credentials_expiration to 1 under the [pam]
section in /etc/sssd/sssd.conf. For example:
[pam] offline_credentials_expiration = 1 |
If cached authentication information is out-of-date, the validity of the authentication information may be questionable. |
| CCE-94725-9 | Install the OpenSSH Server Package |
The openssh-server package should be installed.
The openssh-server package can be installed with the following command:
$ sudo zypper install openssh-server |
Without protection of the transmitted information, confidentiality, and integrity may be compromised because unprotected communications can be intercepted and either read or altered. |
| CCE-94726-7 | Enable the OpenSSH Service |
The SSH server service, sshd, is commonly needed.
The sshd service can be enabled with the following command:
$ sudo systemctl enable sshd.service |
Without protection of the transmitted information, confidentiality, and
integrity may be compromised because unprotected communications can be
intercepted and either read or altered.
This checklist item 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, etc). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. |
| CCE-94727-5 | Restrict Exposed Kernel Pointer Addresses Access |
To set the runtime status of the kernel.kptr_restrict kernel parameter, run the following command: $ sudo sysctl -w kernel.kptr_restrict=1To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.kptr_restrict = 1 |
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 disallow any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with 0. |
| CCE-94728-3 | Enable Randomized Layout of Virtual Address Space |
To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command: $ sudo sysctl -w kernel.randomize_va_space=2To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: kernel.randomize_va_space = 2 |
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's 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 re-purpose it using return oriented programming (ROP) techniques. |
| CCE-94729-1 | Ensure zypper Removes Previous Package Versions | zypper should be configured to remove previous software components after new versions have been installed. To configure zypper to remove the previous software components after updating, set the solver.upgradeRemoveDroppedPackages to 1 in /etc/zypp/zypp.conf. | Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by some adversaries. |
| CCE-94730-9 | Configure Notification of Post-AIDE Scan Details |
AIDE should notify appropriate personnel of the details of a scan after the scan has been run.
If AIDE has already been configured for periodic execution in /etc/crontab, append the
following line to the existing AIDE line:
| /bin/mail -s "$(hostname) - AIDE Integrity Check" root@localhostOtherwise, add the following line to /etc/crontab: 05 4 * * * root /usr/bin/aide --check | /bin/mail -s "$(hostname) - AIDE Integrity Check" root@localhostAIDE can be executed periodically through other means; this is merely one example. |
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. |
| CCE-94731-7 | Record Unsuccessful Delete Attempts to Files - rename |
The audit system should collect unsuccessful file deletion
attempts for all users and root. If the auditd daemon is configured
to use the augenrules program to read audit rules during daemon
startup (the default), add the following lines to a file with suffix
.rules in the directory /etc/audit/rules.d.
If the auditd daemon is configured to use the auditctl
utility to read audit rules during daemon startup, add the following lines to
/etc/audit/audit.rules file.
-a always,exit -F arch=b32 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete -a always,exit -F arch=b32 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-deleteIf the system is 64 bit then also add the following lines: -a always,exit -F arch=b64 -S rename -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete -a always,exit -F arch=b64 -S rename -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-delete |
Unsuccessful attempts to delete files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise. |
| CCE-94732-5 | Record Attempts to Alter Process and Session Initiation Information utmp |
The audit system already collects process information for all
users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/run/utmp -p wa -k sessionIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /var/run/utmp -p wa -k session |
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion. |
| CCE-94733-3 | Record Attempts to Alter Process and Session Initiation Information wtmp |
The audit system already collects process information for all
users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/wtmp -p wa -k sessionIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /var/log/wtmp -p wa -k session |
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion. |
| CCE-94734-1 | Record Attempts to Alter Process and Session Initiation Information btmp |
The audit system already collects process information for all
users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add the
following lines to a file with suffix .rules in the
directory /etc/audit/rules.d:
-w /var/log/btmp -p wa -k sessionIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add the following lines to /etc/audit/audit.rules: -w /var/log/btmp -p wa -k session |
Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion. |
| CCE-94735-8 | Enable systemd-journal-upload Service |
The systemd-journal-upload service is part of the systemd-journal-remote package
and enables centralized logging by uploading local systemd journal entries to a remote log
server via HTTPS. This service acts as a client that pushes journal data to a remote host
running the systemd-journal-remote receiver service.
The systemd-journal-upload service can be enabled with the following command:
$ sudo systemctl enable systemd-journal-upload.service |
Centralized logging through systemd-journal-upload is essential for security monitoring, incident response, and compliance requirements. Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data stored locally to hide their activities. Remote logging ensures that audit trails remain intact even if the local system is compromised. Additionally, centralized logs facilitate correlation of events across multiple systems, enabling better detection of distributed attacks and security incidents. |
| CCE-94736-6 | Configure systemd-journal-upload URL | SUSE Linux Enterprise Micro 6 must offload rsyslog messages for networked systems in real time and offload standalone systems at least weekly | 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 |
| CCE-94737-4 | Configure systemd-journal-upload TLS parameters: ServerKeyFile, ServerCertificateFile and TrustedCertificateFile | SUSE Linux Enterprise Micro 6 must offload rsyslog messages for networked systems in real time and offload standalone systems at least weekly | 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 |
| CCE-94738-2 | Install systemd-journal-remote Package | Journald (via systemd-journal-remote ) supports the ability to send log events it gathers to a remote log host or to receive messages from remote hosts, thus enabling centralised log management. | Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data that is stored on the local system. |
| CCE-94739-0 | Configure audispd's Plugin network_failure_action On Network Failure |
Configure the action the operating system takes if there is an error sending
audit records to a remote system. Edit the file /etc/audit/audisp-remote.conf.
Add or modify the following line, substituting ACTION appropriately:
network_failure_action = ACTIONSet this value to single to cause the system to switch to single user mode for corrective action. Acceptable values also include syslog and halt. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. This profile configures the action to be single. |
Taking appropriate action when there is an error sending audit records to a remote system will minimize the possibility of losing audit records. |
| CCE-94740-8 | Configure audispd's Plugin disk_full_action When Disk Is Full |
Configure the action the operating system takes if the disk the audit records
are written to becomes full. Edit the file /etc/audit/audisp-remote.conf.
Add or modify the following line, substituting ACTION appropriately:
disk_full_action = ACTIONSet this value to single to cause the system to switch to single user mode for corrective action. Acceptable values also include syslog and halt. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. |
Taking appropriate action in case of a filled audit storage volume will minimize the possibility of losing audit records. |
| CCE-94741-6 | Set Password Retry Limit | The pam_cracklib module's retry parameter controls the maximum number of times to prompt the user for the password before returning with error. Make sure it is configured with a value that is no more than 3. For example, retry=1. | To reduce opportunities for successful guesses and brute-force attacks. |
| CCE-94742-4 | Enforce Delay After Failed Logon Attempts |
To configure the system to introduce a delay after failed logon attempts,
add or correct the pam_faildelay settings in
/etc/pam.d/common-auth to make sure its delay parameter
is at least 4000000 or greater. For example:
auth required pam_faildelay.so delay=4000000 |
Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account. |
| CCE-94743-2 | Verify '/proc/sys/crypto/fips_enabled' exists |
On a system where FIPS 140-2 mode is enabled, /proc/sys/crypto/fips_enabled must exist.
To verify FIPS mode, run the following command:
cat /proc/sys/crypto/fips_enabled |
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. |
| CCE-95034-5 | Ensure the Logon Failure Delay is Set Correctly in login.defs |
To ensure the logon failure delay controlled by /usr/etc/login.defs is set properly,
add or correct the FAIL_DELAY setting in /usr/etc/login.defs to read as follows:
FAIL_DELAY 4 |
Increasing the time between a failed authentication attempt and re-prompting to enter credentials helps to slow a single-threaded brute force attack. |
| CCE-95035-2 | The Installed Operating System Is Vendor Supported | The installed operating system must be maintained by a vendor. SUSE Linux Enterprise is supported by SUSE. As the SUSE Linux Enterprise vendor, SUSE is responsible for providing security patches. | An operating system 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 any security issue discovered in the system software. |
| CCE-95036-0 | Ensure Software Patches Installed |
If the system is configured for online updates, invoking the following command will list available
security updates:
$ sudo zypper refresh && sudo zypper list-patches -g security NOTE: U.S. Defense systems are required to be patched within 30 days or sooner as local policy dictates. |
Installing software updates is a fundamental mitigation against the exploitation of publicly-known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise. |
| CCE-95037-8 | Ensure PAM Displays Last Logon/Access Notification |
To configure the system to notify users of last logon/access using pam_lastlog,
add or correct the pam_lastlog settings in /etc/pam.d/postlogin-session
to include showfailed option, such as:
session required pam_lastlog2.so showfailedAnd make sure that the silent option is not set for this specific line. |
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. |
| CCE-95038-6 | Only Authorized Local User Accounts Exist on Operating System |
Enterprise Application tends to use the server or virtual machine exclusively.
Besides the default operating system user, there should be only authorized local
users required by the installed software groups and applications that exist on
the operating system. The authorized user list can be customized in the refine
value variable var_accounts_authorized_local_users_regex.
OVAL regular expression is used for the user list.
Configure the system so all accounts on the system are assigned to an active system,
application, or user account. Remove accounts that do not support approved system
activities or that allow for a normal user to perform administrative-level actions.
To remove unauthorized system accounts, use the following command:
$ sudo userdel unauthorized_user |
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. |
| CCE-95039-4 | Ensure that System Accounts Do Not Run a Shell Upon Login |
Some accounts are not associated with a human user of the system, and exist to perform some
administrative functions. Should an attacker be able to log into these accounts, they should
not be granted access to a shell.
The login shell for each local account is stored in the last field of each line in /etc/passwd. System accounts are those user accounts with a user ID less than 1000. The user ID is stored in the third field. If any system account other than root has a login shell, disable it with the command: $ sudo usermod -s /sbin/nologin account |
Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts. |
| CCE-95040-2 | Ensure sudo only includes the default configuration directory | Administrators can configure authorized sudo users via drop-in files, and it is possible to include other directories and configuration files from the file currently being parsed. Make sure that /etc/sudoers only includes drop-in configuration files from /etc/sudoers.d, or that no drop-in file is included. Either the /etc/sudoers should contain only one #includedir directive pointing to /etc/sudoers.d, and no file in /etc/sudoers.d/ should include other files or directories; Or the /etc/sudoers should not contain any #include, @include, #includedir or @includedir directives. Note that the '#' character doesn't denote a comment in the configuration file. | Some sudo configuration options allow users to run programs without re-authenticating. Use of these configuration options makes it easier for one compromised account to be used to compromise other accounts. |
| CCE-95041-0 | Verify Only Root Has UID 0 |
If any account other than root has a UID of 0, this misconfiguration should
be investigated and the accounts other than root should be removed or have
their UID changed.
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 greater than "1000" that has not already been assigned. |
An account has root authority if it has a 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. |
| CCE-95042-8 | The operating system must restrict privilege elevation to authorized personnel | The sudo command allows a user to execute programs with elevated (administrator) privileges. It prompts the user for their password and confirms your request to execute a command by checking a file, called sudoers. Restrict privileged actions by removing the following entries from the sudoers file: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL | If the "sudoers" file is not configured correctly, any user defined on the system can initiate privileged actions on the target system. |
| CCE-95043-6 | Ensure invoking users password for privilege escalation when using sudo |
The sudoers security policy requires that users authenticate themselves before they can use sudo.
When sudoers requires authentication, it validates the invoking user's credentials.
The expected output for:
sudo cvtsudoers -f sudoers /etc/sudoers | grep -E '^Defaults !?(rootpw|targetpw|runaspw)$' Defaults !targetpw
Defaults !rootpw
Defaults !runaspw
or if cvtsudoers not supported:
sudo find /etc/sudoers /etc/sudoers.d \( \! -name '*~' -a \! -name '*.*' \) -exec grep -E --with-filename '^[[:blank:]]*Defaults[[:blank:]](.*[[:blank:]])?!?\b(rootpw|targetpw|runaspw)' -- {} \;
/etc/sudoers:Defaults !targetpw
/etc/sudoers:Defaults !rootpw
/etc/sudoers:Defaults !runaspw
|
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. |
| CCE-95044-4 | Ensure Home Directories are Created for New Users |
All local interactive user accounts, upon creation, should be assigned a home directory.
Configure the operating system to assign home directories to all new local interactive users by setting the CREATE_HOME parameter in /usr/etc/login.defs to yes as follows: CREATE_HOME yes |
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. |
| CCE-95045-1 | Enable SSH Print Last Log |
Ensure that SSH will display the date and time of the last successful account logon.
The default SSH configuration enables print of the date and time of the last login. The appropriate configuration is used if no value is set for PrintLastLog. To explicitly enable LastLog in SSH, add or correct the following line in /etc/ssh/sshd_config: PrintLastLog yes |
Providing users feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use. |
| CCE-95046-9 | Ensure There Are No Accounts With Blank or Null Passwords |
Check the "/etc/shadow" file for blank passwords 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 the system to have a password or lock
the account with the following commands:
Perform a password reset:
$ sudo passwd [username]Lock an account: $ sudo passwd -l [username] |
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. |
| CCE-95047-7 | Prevent Login to Accounts With Empty Password | If an account is configured for password authentication but does not have an assigned password, it may be possible to log into the account without authentication. Remove any instances of the nullok in password authentication configurations in /etc/pam.d/ to prevent logins with empty passwords. | 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. |
| CCE-95048-5 | Ensure /var/log/audit Located On Separate Partition |
Audit logs are stored in the /var/log/audit directory.
Ensure that /var/log/audit has its own partition or logical
volume at installation time, or migrate it using LVM.
Make absolutely certain that it is large enough to store all
audit logs that will be created by the auditing daemon.
|
Placing /var/log/audit in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space. |
| CCE-95049-3 | Remove User Host-Based Authentication Files |
The ~/.shosts (in each user's home directory) files
list remote hosts and users that are trusted by the
local system. To remove these files, run the following command
to delete them from any location:
$ sudo find / -name '.shosts' -type f -delete |
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. |
| CCE-95051-9 | Remove Host-Based Authentication Files |
The shosts.equiv file lists remote hosts and users that are trusted by the local
system. To remove these files, run the following command to delete them from any location:
$ sudo rm /[path]/[to]/[file]/shosts.equiv |
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. |
| CCE-95052-7 | Configure AIDE to Verify Access Control Lists (ACLs) |
By default, the acl option is added to the FIPSR ruleset in AIDE.
If using a custom ruleset or the acl option is missing, add acl
to the appropriate ruleset.
For example, add acl to the following line in /etc/aide.conf:
FIPSR = p+i+n+u+g+s+m+c+acl+selinux+xattrs+sha256AIDE rules can be configured in multiple ways; this is merely one example that is already configured by default. The remediation provided with this rule adds acl to all rule sets available in /etc/aide.conf |
ACLs can provide permissions beyond those permitted through the file mode and must be verified by the file integrity tools. |
| CCE-95053-5 | Configure AIDE to Verify Extended Attributes |
By default, the xattrs option is added to the FIPSR ruleset in AIDE.
If using a custom ruleset or the xattrs option is missing, add xattrs
to the appropriate ruleset.
For example, add xattrs to the following line in /etc/aide.conf:
FIPSR = p+i+n+u+g+s+m+c+acl+selinux+xattrs+sha256AIDE rules can be configured in multiple ways; this is merely one example that is already configured by default. The remediation provided with this rule adds xattrs to all rule sets available in /etc/aide.conf |
Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications. |
| CCE-95054-3 | Disable Ctrl-Alt-Del Reboot Activation |
By default, SystemD will reboot the system if the Ctrl-Alt-Del
key sequence is pressed.
To configure the system to ignore the Ctrl-Alt-Del key sequence from the command line instead of rebooting the system, do either of the following: ln -sf /dev/null /etc/systemd/system/ctrl-alt-del.targetor systemctl mask ctrl-alt-del.target Do not simply delete the /usr/lib/systemd/system/ctrl-alt-del.service file, as this file may be restored during future system updates. |
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. |
| CCE-95055-0 | All Interactive Users Must Have A Home Directory Defined | Assign home directories to all interactive users that currently do not have a home directory assigned. This rule checks if the home directory is properly defined in a folder which has at least one parent folder, like "user" in "/home/user" or "/remote/users/user". Therefore, this rule will report a finding for home directories like /users, /tmp or /. | 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. |
| CCE-95056-8 | All Interactive Users Home Directories Must Exist |
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:
$ sudo mkdir /home/USER |
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. |
| CCE-95057-6 | All Interactive User Home Directories Must Have mode 0750 Or Less Permissive |
Change the mode of interactive users home directories to 0750. To
change the mode of interactive users home directory, use the
following command:
$ sudo chmod 0750 /home/USER |
Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users. |
| CCE-95058-4 | All Interactive User Home Directories Must Be Group-Owned By The Primary Group |
Change the group owner of interactive users home directory to the
group found in /etc/passwd. To change the group owner of
interactive users home directory, use the following command:
$ sudo chgrp USER_GROUP /home/USERThis rule ensures every home directory related to an interactive user is group-owned by an interactive user. It also ensures that interactive users are group-owners of one and only one home directory. |
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. |
| CCE-95059-2 | Ensure All User Initialization Files Have Mode 0740 Or Less Permissive |
Set the mode of the user initialization files to 0740 with the
following command:
$ sudo chmod 0740 /home/USER/.INIT_FILE |
Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon. |
| CCE-95060-0 | Ensure that Users Path Contains Only Local Directories | Ensure that all interactive user initialization files executable search path statements do not contain statements that will reference a working directory other than the users home directory. | 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). |
| CCE-95061-8 | User Initialization Files Must Not Run World-Writable Programs |
Set the mode on files being executed by the user initialization files with the
following command:
$ sudo chmod o-w FILE |
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. |
| CCE-95062-6 | Add nosuid Option to /home |
The nosuid mount option can be used to prevent
execution of setuid programs in /home. The SUID and SGID permissions
should not be required in these user data directories.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
/home.
|
The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions. |
| CCE-95063-4 | Add nosuid Option to Removable Media Partitions |
The nosuid mount option prevents set-user-identifier (SUID)
and set-group-identifier (SGID) permissions from taking effect. These permissions
allow users to execute binaries with the same permissions as the owner and group
of the file respectively. Users should not be allowed to introduce SUID and SGID
files into the system via partitions mounted from removable media.
Add the nosuid option to the fourth column of
/etc/fstab for the line which controls mounting of
any removable media partitions.
|
The presence of SUID and SGID executables should be tightly controlled. Allowing users to introduce SUID or SGID binaries from partitions mounted off of removable media would allow them to introduce their own highly-privileged programs. |
| CCE-95064-2 | Ensure All World-Writable Directories Are Group Owned by a System Account | All directories in local partitions which are world-writable should be group owned by root or another system account. If any world-writable directories are not group owned by a system account, this should be investigated. Following this, the files should be deleted or assigned to an appropriate group. | Allowing a user account to group own a world-writable directory is undesirable because it allows the owner of that directory to remove or replace any files that may be placed in the directory by other users. |
| CCE-95065-9 | Disable KDump Kernel Crash Analyzer (kdump) |
The kdump service provides a kernel crash dump analyzer. It uses the kexec
system call to boot a secondary kernel ("capture" kernel) following a system
crash, which can load information from the crashed kernel for analysis.
The kdump service can be disabled with the following command:
$ sudo systemctl mask --now kdump.service |
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. |
| CCE-95066-7 | Ensure /home Located On Separate Partition | If user home directories will be stored locally, create a separate partition for /home at installation time (or migrate it later using LVM). If /home will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later. | 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. |
| CCE-95067-5 | Ensure /var Located On Separate Partition | The /var directory is used by daemons and other system services to store frequently-changing data. Ensure that /var has its own partition or logical volume at installation time, or migrate it using LVM. | 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. |
| CCE-95068-3 | Disable SSH Support for User Known Hosts |
SSH can allow system users to connect to systems if a cache of the remote
systems public keys is available. This should be disabled.
To ensure this behavior is disabled, add or correct the following line in /etc/ssh/sshd_config: IgnoreUserKnownHosts yes |
Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere. |
| CCE-95069-1 | Verify Permissions on SSH Server Public *.pub Key Files |
To properly set the permissions of /etc/ssh/*.pub, run the command: $ sudo chmod 0644 /etc/ssh/*.pub |
If a public host key file is modified by an unauthorized user, the SSH service may be compromised. |
| CCE-95070-9 | Verify Permissions on SSH Server Private *_key Key Files |
SSH server private keys - files that match the /etc/ssh/*_key glob, have to have restricted permissions.
If those files are owned by the root user and the root group, they have to have the 0640 permission or stricter.
|
If an unauthorized user obtains the private SSH host key file, the host could be impersonated. |
| CCE-95071-7 | Enable Use of Strict Mode Checking |
SSHs StrictModes option checks file and ownership permissions in
the user's home directory .ssh folder before accepting login. If world-
writable permissions are found, logon is rejected.
The default SSH configuration has StrictModes enabled. The appropriate configuration is used if no value is set for StrictModes. To explicitly enable StrictModes in SSH, add or correct the following line in /etc/ssh/sshd_config: StrictModes yes |
If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user. |
| CCE-95072-5 | Disable X11 Forwarding |
The X11Forwarding parameter provides the ability to tunnel X11 traffic
through the connection to enable remote graphic connections.
SSH has the capability to encrypt remote X11 connections when SSH's
X11Forwarding option is enabled.
The default SSH configuration disables X11Forwarding. The appropriate configuration is used if no value is set for X11Forwarding. To explicitly disable X11 Forwarding, add or correct the following line in /etc/ssh/sshd_config: X11Forwarding no |
Disable X11 forwarding unless there is an operational requirement to use X11 applications directly. There is a small risk that the remote X11 servers of users who are logged in via SSH with X11 forwarding could be compromised by other users on the X11 server. Note that even if X11 forwarding is disabled, users can always install their own forwarders. |
| CCE-95073-3 | Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces |
To set the runtime status of the net.ipv4.conf.all.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.accept_source_route = 0 |
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 should be disabled unless it is absolutely required. |
| CCE-95074-1 | Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces |
To set the runtime status of the net.ipv6.conf.all.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.accept_source_route = 0 |
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 IPv6 forwarding is enabled and
the system is functioning as a router.
Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required. |
| CCE-95075-8 | Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default |
To set the runtime status of the net.ipv4.conf.default.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.accept_source_route = 0 |
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 should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router. |
| CCE-95076-6 | Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default |
To set the runtime status of the net.ipv6.conf.default.accept_source_route kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.accept_source_route = 0 |
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 IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required. |
| CCE-95077-4 | Disable Accepting ICMP Redirects for All IPv4 Interfaces |
To set the runtime status of the net.ipv4.conf.all.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.accept_redirects = 0 |
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." |
| CCE-95078-2 | Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces |
To set the runtime status of the net.ipv4.conf.default.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.accept_redirects = 0 |
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. |
| CCE-95079-0 | Disable Accepting ICMP Redirects for All IPv6 Interfaces |
To set the runtime status of the net.ipv6.conf.all.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.accept_redirects = 0 |
An illicit ICMP redirect message could result in a man-in-the-middle attack. |
| CCE-95080-8 | Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces |
To set the runtime status of the net.ipv6.conf.default.accept_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.accept_redirects = 0 |
An illicit ICMP redirect message could result in a man-in-the-middle attack. |
| CCE-95081-6 | Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default |
To set the runtime status of the net.ipv4.conf.default.send_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.default.send_redirects = 0 |
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. |
| CCE-95082-4 | Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces |
To set the runtime status of the net.ipv4.conf.all.send_redirects kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.conf.all.send_redirects = 0 |
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. |
| CCE-95083-2 | Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces |
To set the runtime status of the net.ipv4.ip_forward kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.ip_forward=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv4.ip_forward = 0 |
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. |
| CCE-95084-0 | Disable Kernel Parameter for IPv6 Forwarding |
To set the runtime status of the net.ipv6.conf.all.forwarding kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.all.forwarding=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.all.forwarding = 0 |
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. |
| CCE-95085-7 | Disable Kernel Parameter for IPv6 Forwarding by default |
To set the runtime status of the net.ipv6.conf.default.forwarding kernel parameter, run the following command: $ sudo sysctl -w net.ipv6.conf.default.forwarding=0To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d: net.ipv6.conf.default.forwarding = 0 |
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. |
| CCE-95086-5 | Ensure System is Not Acting as a Network Sniffer |
The system should not be acting as a network sniffer, which can
capture all traffic on the network to which it is connected. Run the following
to determine if any interface is running in promiscuous mode:
$ ip link | grep PROMISCPromiscuous mode of an interface can be disabled with the following command: $ sudo ip link set dev device_name multicast off promisc off |
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 Manager (ISSM) and restricted to only authorized personnel. |
| CCE-95087-3 | Ensure All Files Are Owned by a User |
If any files are not owned by a user, then the cause of their lack of ownership should be
investigated. Following this, the files should be deleted or assigned to an appropriate user.
Locate the mount points related to local devices by the following command:
$ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which
do not belong to a valid user using the following command:
$ sudo find MOUNTPOINT -xdev -nouser 2>/dev/null |
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account, or other similar cases. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed. |
| CCE-95088-1 | Ensure All Files Are Owned by a Group |
If any file is not group-owned by a valid defined group, the cause of the lack of
group-ownership must be investigated. Following this, those files should be deleted or
assigned to an appropriate group. The groups need to be defined in /etc/group
or in /usr/lib/group if nss-altfiles are configured to be used
in /etc/nsswitch.conf.
Locate the mount points related to local devices by the following command:
$ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which
do not belong to a valid group using the following command:
$ sudo find MOUNTPOINT -xdev -nogroup 2>/dev/null |
Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account, or other similar cases. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed. |
| CCE-95089-9 | Ensure the Default Umask is Set Correctly in login.defs |
To ensure the default umask controlled by /usr/etc/login.defs is set properly,
add or correct the UMASK setting in /usr/etc/login.defs to read as follows:
UMASK 027 |
The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read and written to by unauthorized users. |
| CCE-95090-7 | Do Not Allow SSH Environment Options |
Ensure that users are not able to override environment variables of the SSH daemon.
The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for PermitUserEnvironment. To explicitly disable Environment options, add or correct the following /etc/ssh/sshd_config: PermitUserEnvironment no |
SSH environment options potentially allow users to bypass access restriction in some configurations. |
| CCE-95091-5 | Disable SSH Access via Empty Passwords |
Disallow SSH login with empty passwords.
The default SSH configuration disables logins with empty passwords. The appropriate
configuration is used if no value is set for PermitEmptyPasswords.
To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config: PermitEmptyPasswords noAny accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords. |
Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere. |
| CCE-95092-3 | Ensure SELinux State is Enforcing |
The SELinux state should be set to enforcing at
system boot time. In the file /etc/selinux/config, add or correct the
following line to configure the system to boot into enforcing mode:
SELINUX=enforcingEnsure that all files have correct SELinux labels by running: fixfiles onbootThen reboot the system. |
Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges. |
| CCE-95093-1 | Install policycoreutils Package |
The policycoreutils package can be installed with the following command:
$ sudo zypper install policycoreutils |
Security-enhanced Linux is a feature of the Linux kernel and a number of utilities with enhanced security functionality designed to add mandatory access controls to Linux. The Security-enhanced Linux kernel contains new architectural components originally developed to improve security of the Flask operating system. These architectural components provide general support for the enforcement of many kinds of mandatory access control policies, including those based on the concepts of Type Enforcement, Role-based Access Control, and Multi-level Security. 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, setfiles to label filesystems, newrole to switch roles, and so on. |
| CCE-95094-9 | Configure SELinux Policy |
The SELinux targeted policy is appropriate for
general-purpose desktops and servers, as well as systems in many other roles.
To configure the system to use this policy, add or correct the following line
in /etc/selinux/config:
SELINUXTYPE=targetedOther policies, such as mls, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases. |
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 . |
| CCE-95095-6 | Record Any Attempts to Run semanage |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-95096-4 | Install policycoreutils-python-utils package |
The policycoreutils-python-utils package can be installed with the following command:
$ sudo zypper install policycoreutils-python-utils |
This package is required to operate and manage an SELinux environment and its policies. It provides utilities such as semanage, audit2allow, audit2why, chcat and sandbox. |
| CCE-95097-2 | Record Any Attempts to Run setfiles |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-95098-0 | Record Any Attempts to Run setsebool |
At a minimum, the audit system should collect the execution of privileged
commands for all users and root.
If the auditd daemon is configured to use the augenrules
program to read audit rules during daemon startup (the default), add
a line of the following form to a file with suffix .rules
in the directory /etc/audit/rules.d:
-a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privilegedIf the auditd daemon is configured to use the auditctl utility to read audit rules during daemon startup, add a line of the following form to /etc/audit/audit.rules: -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged |
Misuse of privileged functions, either intentionally or unintentionally by
authorized users, or by unauthorized external entities that have compromised 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 and advanced persistent threats.
Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity. |
| CCE-95099-8 | Map System Users To The Appropriate SELinux Role |
Configure the operating system to prevent non-privileged users from executing
privileged functions to include disabling, circumventing, or altering
implemented security safeguards/countermeasures. All administrators must be
mapped to the sysadm_u or staff_u users with the
appropriate domains (sysadm_t and staff_t).
$ sudo semanage login -m -s sysadm_u USERor $ sudo semanage login -m -s staff_u USER All authorized non-administrative users must be mapped to the user_u role or the appropriate domain (user_t). $ sudo semanage login -m -s user_u USER |
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 who 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. |
| CCE-95100-4 | Verify that System Executable Directories Have Restrictive Permissions |
System executables are stored in the following directories by default:
/bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbinThese directories should not be group-writable or world-writable. If any directory DIR in these directories is found to be group-writable or world-writable, correct its permission with the following command: $ sudo chmod go-w DIR |
System binaries are executed by privileged users, as well as system services, and restrictive permissions are necessary to ensure execution of these programs cannot be co-opted. |