Group
Guide to the Secure Configuration of SUSE Linux Enterprise 15
Group contains 85 groups and 251 rules |
Group
System Settings
Group contains 53 groups and 131 rules |
[ref]
Contains rules that check correct system settings. |
Group
Installing and Maintaining Software
Group contains 10 groups and 24 rules |
[ref]
The following sections contain information on
security-relevant choices during the initial operating system
installation process and the setup of software
updates. |
Group
System and Software Integrity
Group contains 4 groups and 8 rules |
[ref]
System and software integrity can be gained by installing antivirus, increasing
system encryption strength with FIPS, verifying installed software, enabling SELinux,
installing an Intrusion Prevention System, etc. However, installing or enabling integrity
checking tools cannot prevent intrusions, but they can detect that an intrusion
may have occurred. Requirements for integrity checking may be highly dependent on
the environment in which the system will be used. Snapshot-based approaches such
as AIDE may induce considerable overhead in the presence of frequent software updates. |
Group
Software Integrity Checking
Group contains 2 groups and 6 rules |
[ref]
Both the AIDE (Advanced Intrusion Detection Environment)
software and the RPM package management system provide
mechanisms for verifying the integrity of installed software.
AIDE uses snapshots of file metadata (such as hashes) and compares these
to current system files in order to detect changes.
The RPM package management system can conduct integrity
checks by comparing information in its metadata database with
files installed on the system. |
Group
Verify Integrity with RPM
Group contains 3 rules |
[ref]
The RPM package management system includes the ability
to verify the integrity of installed packages by comparing the
installed files with information about the files taken from the
package metadata stored in the RPM database. Although an attacker
could corrupt the RPM database (analogous to attacking the AIDE
database as described above), this check can still reveal
modification of important files. To list which files on the system differ from what is expected by the RPM database:
$ rpm -qVa
See the man page for rpm to see a complete explanation of each column. |
Rule
Verify File Hashes with RPM
[ref] | Without cryptographic integrity protections, system executables and files can be altered by
unauthorized users without detection. The RPM package management system can check the hashes
of installed software packages, including many that are important to system security.
To verify that the cryptographic hash of system files and commands matches vendor values, run
the following command to list which files on the system have hashes that differ from what is
expected by the RPM database:
$ rpm -Va --noconfig | grep '^..5'
If the file was not expected to change, investigate the cause of the change using audit logs
or other means. The package can then be reinstalled to restore the file. Run the following
command to determine which package owns the file:
$ rpm -qf FILENAME
The package can be reinstalled from a zypper repository using the command:
$ sudo zypper reinstall PACKAGENAME
Alternatively, the package can be reinstalled from trusted media using the command:
$ sudo rpm -Uvh PACKAGENAME
Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of packages present on the system. It is not a
problem in most cases, but especially systems with a large number of installed packages
can be affected. | Rationale: | The hashes of important files like system executables should match the
information given by the RPM database. Executables with erroneous hashes could
be a sign of nefarious activity on the system. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_rpm_verify_hashes | Identifiers: | CCE-85788-8 | References: | cis-csc | 11, 2, 3, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02 | cui | 3.3.8, 3.4.1 | disa | CCI-000366, CCI-001749 | hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i) | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4 | nist | CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3) | nist-csf | PR.DS-6, PR.DS-8, PR.IP-1 | pcidss | Req-11.5 | os-srg | SRG-OS-000480-GPOS-00227 | pcidss4 | 11.5.2 |
| |
|
Rule
Verify and Correct Ownership with RPM
[ref] | The RPM package management system can check file ownership permissions of installed software
packages, including many that are important to system security. After locating a file with
incorrect permissions, which can be found with:
rpm -Va | awk '{ if (substr($0,6,1)=="U" || substr($0,7,1)=="G") print $NF }'
run the following command to determine which package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --setugids PACKAGENAME
Warning:
Profiles may require that specific files be owned by root while the default owner defined
by the vendor is different. Such files will be reported as a finding and need to be
evaluated according to your policy and deployment environment. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of packages present on the system. It is not a
problem in most cases, but especially systems with a large number of installed packages
can be affected. | Rationale: | Ownership of binaries and configuration files that is incorrect could allow an unauthorized
user to gain privileges that they should not have. The ownership set by the vendor should be
maintained. Any deviations from this baseline should be investigated. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_rpm_verify_ownership | Identifiers: | CCE-91290-7 | References: | cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01 | cui | 3.3.8, 3.4.1 | disa | CCI-001494, CCI-001496 | isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4 | isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2 | nist | CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3) | nist-csf | PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1 | pcidss | Req-11.5 | os-srg | SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000278-GPOS-00108 | cis | 6.1.1 | pcidss4 | 11.5.2 |
| |
|
Rule
Verify and Correct File Permissions with RPM
[ref] | The RPM package management system can check file access permissions of installed software
packages, including many that are important to system security. Verify that the file
permissions of system files and commands match vendor values. Check the file permissions with
the following command:
$ sudo rpm -Va | awk '{ if (substr($0,2,1)=="M") print $NF }'
Output indicates files that do not match vendor defaults.
After locating a file with incorrect permissions, run the following command to determine which
package owns it:
$ rpm -qf FILENAME
Next, run the following command to reset its permissions to the correct values:
$ sudo rpm --setperms PACKAGENAME
Warning:
Profiles may require that specific files have stricter file permissions than defined by
the vendor. Such files will be reported as a finding and need to be evaluated according to
your policy and deployment environment. Warning:
This rule can take a long time to perform the check and might consume a considerable
amount of resources depending on the number of packages present on the system. It is not a
problem in most cases, but especially systems with a large number of installed packages
can be affected. | Rationale: | Permissions on system binaries and configuration files that are too generous could allow an
unauthorized user to gain privileges that they should not have. The permissions set by the
vendor should be maintained. Any deviations from this baseline should be investigated. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_rpm_verify_permissions | Identifiers: | CCE-85782-1 | References: | cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.07, DSS06.02, MEA02.01 | cui | 3.3.8, 3.4.1 | disa | CCI-001493, CCI-001494, CCI-001495, CCI-001496 | hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i) | isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4 | isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 7.6 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2 | nist | CM-6(d), CM-6(c), SI-7, SI-7(1), SI-7(6), AU-9(3), CM-6(a) | nist-csf | PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1 | pcidss | Req-11.5 | os-srg | SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099, SRG-OS-000278-GPOS-00108 | cis | 6.1.1 | pcidss4 | 11.5.2 |
| |
|
Group
Verify Integrity with AIDE
Group contains 3 rules |
[ref]
AIDE conducts integrity checks by comparing information about
files with previously-gathered information. Ideally, the AIDE database is
created immediately after initial system configuration, and then again after any
software update. AIDE is highly configurable, with further configuration
information located in /usr/share/doc/aide-VERSION
. |
Rule
Install AIDE
[ref] | The aide package can be installed with the following command:
$ sudo zypper install aide
| Rationale: | The AIDE package must be installed if it is to be available for integrity checking. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_package_aide_installed | Identifiers: | CCE-83289-9 | References: | cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9 | cjis | 5.10.1.3 | cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06 | disa | CCI-002696, CCI-002699, CCI-001744 | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6 | ism | 1034, 1288, 1341, 1417 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3 | nist | CM-6(a) | nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3 | pcidss | Req-11.5 | os-srg | SRG-OS-000445-GPOS-00199 | stigid | SLES-15-010419 | cis | 1.4.1 | anssi | R76, R79 | pcidss4 | 11.5.2 | stigref | SV-255922r958794_rule |
| |
|
Rule
Build and Test AIDE Database
[ref] | Run the following command to generate a new database:
$ sudo /usr/bin/aide --init
By 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.db
To initiate a manual check, run the following command:
$ sudo /usr/bin/aide --check
If this check produces any unexpected output, investigate. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_aide_build_database | Identifiers: | CCE-85787-0 | References: | cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9 | cjis | 5.10.1.3 | cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06 | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3 | nist | CM-6(a) | nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3 | pcidss | Req-11.5 | os-srg | SRG-OS-000445-GPOS-00199 | stigid | SLES-15-010419 | cis | 1.4.1 | anssi | R76, R79 | pcidss4 | 11.5.2 | stigref | SV-255922r958794_rule |
| |
|
Rule
Configure Systemd Timer Execution of AIDE
[ref] | 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. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_aide_periodic_checking_systemd_timer | Identifiers: | CCE-92516-4 | References: | cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9 | cjis | 5.10.1.3 | cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06 | disa | CCI-001744, CCI-002699, CCI-002702 | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3 | nist | SI-6(d) | nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3 | pcidss | Req-11.5 | os-srg | SRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201 | stigid | SLES-15-010570 | cis | 1.4.2 | anssi | R76 | pcidss4 | 11.5.2 | stigref | SV-234864r958948_rule |
| |
|
Group
System Cryptographic Policies
Group contains 2 rules |
[ref]
Linux has the capability to centrally configure cryptographic polices. The command
update-crypto-policies is used to set the policy applicable for the various
cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic
policies will be the default policy used by these backends unless the application
user configures them otherwise. When the system has been configured to use the
centralized cryptographic policies, the administrator is assured that any application
that utilizes the supported backends will follow a policy that adheres to the
configured profile.
Currently the supported backends are:
- GnuTLS library
- OpenSSL library
- NSS library
- OpenJDK
- Libkrb5
- BIND
- OpenSSH
Applications and languages which rely on any of these backends will follow the
system policies as well. Examples are apache httpd, nginx, php, and others. |
Rule
Configure System Cryptography Policy
[ref] | To configure the system cryptography policy to use ciphers only from the DEFAULT
policy, run the following command:
$ sudo update-crypto-policies --set DEFAULT
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the /etc/crypto-policies/back-ends are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied.
Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon. Warning:
The system needs to be rebooted for these changes to take effect. Warning:
System Crypto Modules must be provided by a vendor that undergoes
FIPS-140 certifications.
FIPS-140 is applicable to all Federal agencies that use
cryptographic-based security systems to protect sensitive information
in computer and telecommunication systems (including voice systems) as
defined in Section 5131 of the Information Technology Management Reform
Act of 1996, Public Law 104-106. This standard shall be used in
designing and implementing cryptographic modules that Federal
departments and agencies operate or are operated for them under
contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf
To meet this, the system has to have cryptographic software provided by
a vendor that has undergone this certification. This means providing
documentation, test results, design information, and independent third
party review by an accredited lab. While open source software is
capable of meeting this, it does not meet FIPS-140 unless the vendor
submits to this process. | Rationale: | Centralized cryptographic policies simplify applying secure ciphers across an operating system and
the applications that run on that operating system. Use of weak or untested encryption algorithms
undermines the purposes of utilizing encryption to protect data. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_configure_crypto_policy | Identifiers: | CCE-85776-3 | References: | hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii) | ism | 1446 | nerc-cip | CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1 | nist | AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3) | ospp | FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1 | os-srg | SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174 | pcidss4 | 2.2.7, 2.2 |
| |
|
Rule
Configure SSH to use System Crypto Policy
[ref] | Crypto Policies provide a centralized control over crypto algorithms usage of many packages.
SSH is supported by crypto policy, but the SSH configuration may be
set up to ignore it.
To check that Crypto Policies settings are configured correctly, ensure that
the CRYPTO_POLICY variable is either commented or not set at all
in the /etc/sysconfig/sshd . | Rationale: | Overriding the system crypto policy makes the behavior of the SSH service violate expectations,
and makes system configuration more fragmented. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_configure_ssh_crypto_policy | Identifiers: | CCE-85795-3 | References: | disa | CCI-001453 | hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii) | nerc-cip | CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1 | nist | AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13 | ospp | FCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1 | pcidss | Req-2.2 | os-srg | SRG-OS-000250-GPOS-00093 | pcidss4 | 2.2.7, 2.2 |
| |
|
Group
GNOME Desktop Environment
Group contains 2 groups and 7 rules |
[ref]
GNOME is a graphical desktop environment bundled with many Linux distributions that
allow users to easily interact with the operating system graphically rather than
textually. The GNOME Graphical Display Manager (GDM) provides login, logout, and user
switching contexts as well as display server management.
GNOME is developed by the GNOME Project and is considered the default
Red Hat Graphical environment.
For more information on GNOME and the GNOME Project, see https://www.gnome.org. |
Group
Configure GNOME Login Screen
Group contains 1 rule |
|
Rule
Disable GDM Unattended or Automatic Login
[ref] | The GNOME Display Manager (GDM) can allow users to automatically login without
user interaction or credentials or unattended login. User should always be required to authenticate themselves
to the system that they are authorized to use. To disable user ability to automatically
login to the system, set the DISPLAYMANAGER_AUTOLOGIN=""
or DISPLAYMANAGER_PASSWORD_LESS_LOGIN="no" in the
/etc/sysconfig/displaymanager . For example:
DISPLAYMANAGER_AUTOLOGIN=""
DISPLAYMANAGER_PASSWORD_LESS_LOGIN="no"
| Rationale: | Failure to restrict system access to authenticated users negatively impacts operating
system security. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_gnome_gdm_disable_unattended_automatic_login | Identifiers: | CCE-85723-5 | References: | | |
|
Group
Configure GNOME Screen Locking
Group contains 5 rules |
[ref]
In the default GNOME3 desktop, the screen can be locked
by selecting the user name in the far right corner of the main panel and
selecting Lock.
The following sections detail commands to enforce idle activation of the screensaver,
screen locking, a blank-screen screensaver, and an idle activation time.
Because users should be trained to lock the screen when they
step away from the computer, the automatic locking feature is only
meant as a backup.
The root account can be screen-locked; however, the root account should
never be used to log into an X Windows environment and should only
be used to for direct login via console in emergency circumstances.
For more information about enforcing preferences in the GNOME3 environment using the DConf
configuration system, see http://wiki.gnome.org/dconf and
the man page dconf(1) . |
Rule
Enable GNOME3 Screensaver Idle Activation
[ref] | To activate the screensaver in the GNOME3 desktop after a period of inactivity,
add or set idle-activation-enabled to true in
/etc/dconf/db/local.d/00-security-settings . For example:
[org/gnome/desktop/screensaver]
idle-activation-enabled=true
Once the setting has been added, add a lock to
/etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/screensaver/idle-activation-enabled
After the settings have been set, run dconf update . | Rationale: | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate
physical vicinity of the information system but does not logout because of the temporary nature of the absence.
Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity,
GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the
session lock.
Enabling idle activation of the screensaver ensures the screensaver will
be activated after the idle delay. Applications requiring continuous,
real-time screen display (such as network management products) require the
login session does not have administrator rights and the display station is located in a
controlled-access area. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_idle_activation_enabled | Identifiers: | CCE-85783-9 | References: | cis-csc | 1, 12, 15, 16 | cjis | 5.5.5 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.10 | disa | CCI-000057 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | CM-6(a), AC-11(a) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.8 | os-srg | SRG-OS-000029-GPOS-00010 | pcidss4 | 8.2.8, 8.2 |
| |
|
Rule
Set GNOME3 Screensaver Inactivity Timeout
[ref] | The idle time-out value for inactivity in the GNOME3 desktop is configured via the idle-delay
setting must be set under an appropriate configuration file(s) in the /etc/dconf/db/local.d directory
and locked in /etc/dconf/db/local.d/locks directory to prevent user modification.
For example, to configure the system for a 15 minute delay, add the following to
/etc/dconf/db/local.d/00-security-settings :
[org/gnome/desktop/session]
idle-delay=uint32 900
| Rationale: | A session time-out lock is a temporary action taken when a user stops work and moves away from
the immediate physical vicinity of the information system but does not logout because of the
temporary nature of the absence. Rather than relying on the user to manually lock their operating
system session prior to vacating the vicinity, GNOME3 can be configured to identify when
a user's session has idled and take action to initiate a session lock. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_idle_delay | Identifiers: | CCE-85669-0 | References: | cis-csc | 1, 12, 15, 16 | cjis | 5.5.5 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.10 | disa | CCI-000057, CCI-000060 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | AC-11(a), AC-11.1 (ii) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.8 | os-srg | SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012 | stigid | SLES-15-010120 | pcidss4 | 8.2.8, 8.2 | stigref | SV-234812r958402_rule |
| |
|
Rule
Enable GNOME3 Screensaver Lock After Idle Period
[ref] |
To activate locking of the screensaver in the GNOME3 desktop when it is activated,
run the following command to configure the SUSE operating system to allow the user to lock the GUI:
gsettings set org.gnome.desktop.lockdown disable-lock-screen false
Validate that disable-lock-screen has been set to false with the command:
gsettings get org.gnome.desktop.lockdown disable-lock-screen
| Rationale: | A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity
of the information system but does not want to logout because of the temporary nature of the absense. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_lock_enabled | Identifiers: | CCE-85766-4 | References: | cis-csc | 1, 12, 15, 16 | cjis | 5.5.5 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.10 | disa | CCI-000056, CCI-000058, CCI-000060 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | CM-6(a) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.8 | os-srg | SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011 | stigid | SLES-15-010100 | pcidss4 | 8.2.8, 8.2 | stigref | SV-234810r986461_rule |
| |
|
Rule
Implement Blank Screensaver
[ref] |
On SUSE users should set the screensaver to use publicly viewable images or blank screen
by doing the following:
Find the Settings menu and then navigate to the Background selection section
- Click "Activities" on the top left.
- Click "Show Applications" at the bottom of the Activities menu.
- Click the "Settings" icon.
- Click "Background" from left hand menu.
- Select image and set the Lock Screen image to the user's choice.
- Exit Settings Dialog.
To set the screensaver mode in the GNOME3 desktop to a blank screen,
add or set picture-uri to string '' in
/etc/dconf/db/local.d/00-security-settings . For example:
[org/gnome/desktop/screensaver]
picture-uri=string ''
Once the settings have been added, add a lock to
/etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/screensaver/picture-uri
After the settings have been set, run dconf update . | Rationale: | Setting the screensaver mode to blank-only conceals the
contents of the display from passersby. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_gnome_screensaver_mode_blank | Identifiers: | CCE-85715-1 | References: | cis-csc | 1, 12, 15, 16 | cjis | 5.5.5 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.10 | disa | CCI-000060 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | AC-11(1), CM-6(a), AC-11(1).1 | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.8 | os-srg | SRG-OS-000031-GPOS-00012 | stigid | SLES-15-010140 | pcidss4 | 8.2.8, 8.2 | stigref | SV-234814r958404_rule |
| |
|
Rule
Ensure Users Cannot Change GNOME3 Session Idle Settings
[ref] | If not already configured, ensure that users cannot change GNOME3 session idle settings
by adding /org/gnome/desktop/session/idle-delay
to /etc/dconf/db/local.d/locks/00-security-settings-lock to prevent user modification.
For example:
/org/gnome/desktop/session/idle-delay
After the settings have been set, run dconf update . | Rationale: | A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate
physical vicinity of the information system but does not logout because of the temporary nature of the absence.
Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity,
GNOME desktops can be configured to identify when a user's session has idled and take action to initiate the
session lock. As such, users should not be allowed to change session settings. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_gnome_session_idle_user_locks | Identifiers: | CCE-91245-1 | References: | cis-csc | 1, 12, 15, 16 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.10 | disa | CCI-000057, CCI-000060 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | CM-6(a) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.8 | os-srg | SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012 | stigid | SLES-15-010120 | pcidss4 | 8.2.8, 8.2 | stigref | SV-234812r958402_rule |
| |
|
Rule
Make sure that the dconf databases are up-to-date with regards to respective keyfiles
[ref] | By default, DConf uses a binary database as a data backend.
The system-level database is compiled from keyfiles in the /etc/dconf/db/
directory by the dconf update command. More specifically, content present
in the following directories:
/etc/dconf/db/gdm.d
/etc/dconf/db/local.d
| Rationale: | Unlike text-based keyfiles, the binary database is impossible to check by OVAL.
Therefore, in order to evaluate dconf configuration, both have to be true at the same time -
configuration files have to be compliant, and the database needs to be more recent than those keyfiles,
which gives confidence that it reflects them. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_dconf_db_up_to_date | Identifiers: | CCE-83288-1 | References: | | |
|
Group
Sudo
Group contains 5 rules |
[ref]
Sudo , which stands for "su 'do'", provides the ability to delegate authority
to certain users, groups of users, or system administrators. When configured for system
users and/or groups, Sudo can allow a user or group to execute privileged commands
that normally only root is allowed to execute.
For more information on Sudo and addition Sudo configuration options, see
https://www.sudo.ws. |
Rule
Install sudo Package
[ref] | The sudo package can be installed with the following command:
$ sudo zypper install sudo
| Rationale: | sudo is a program designed to allow a system administrator to give
limited root privileges to users and log root activity. The basic philosophy
is to give as few privileges as possible but still allow system users to
get their work done.
| Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_package_sudo_installed | Identifiers: | CCE-91183-4 | References: | | |
|
Rule
Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty
[ref] | The sudo use_pty tag, when specified, will only execute sudo
commands from users logged in to a real tty.
This should be enabled by making sure that the use_pty tag exists in
/etc/sudoers configuration file or any sudo configuration snippets
in /etc/sudoers.d/ . | Rationale: | Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining
access to the user's terminal after the main program has finished executing. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_sudo_add_use_pty | Identifiers: | CCE-91190-9 | References: | | |
|
Rule
Ensure Sudo Logfile Exists - sudo logfile
[ref] | A custom log sudo file can be configured with the 'logfile' tag. This rule configures
a sudo custom logfile at the default location suggested by CIS, which uses
/var/log/sudo.log. | Rationale: | A sudo log file simplifies auditing of sudo commands. | Severity: | low | Rule ID: | xccdf_org.ssgproject.content_rule_sudo_custom_logfile | Identifiers: | CCE-91311-1 | References: | | |
|
Rule
Ensure Users Re-Authenticate for Privilege Escalation - sudo
[ref] | 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/ ." | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_sudo_require_authentication | Identifiers: | CCE-85673-2 | References: | cis-csc | 1, 12, 15, 16, 5 | cobit5 | DSS05.04, DSS05.10, DSS06.03, DSS06.10 | disa | CCI-002038, CCI-004895 | isa-62443-2009 | 4.3.3.5.1, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-11, CM-6(a) | nist-csf | PR.AC-1, PR.AC-7 | os-srg | SRG-OS-000373-GPOS-00156 | stigid | SLES-15-010450 | pcidss4 | 2.2.6, 2.2 | stigref | SV-234853r987879_rule |
| |
|
Rule
Require Re-Authentication When Using the sudo Command
[ref] | 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. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_sudo_require_reauthentication | Identifiers: | CCE-85764-9 | References: | disa | CCI-002038 | nist | IA-11 | os-srg | SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158 | stigid | SLES-15-020102 | pcidss4 | 2.2.6, 2.2 | stigref | SV-234878r987879_rule |
| |
|
Group
Updating Software
Group contains 4 rules |
[ref]
The zypper command line tool is used to install and
update software packages. The system also provides a graphical
software update tool in the System menu, in the Administration submenu,
called Software Update.
SUSE Linux Enterprise 15 systems contain an installed software catalog called
the RPM database, which records metadata of installed packages. Consistently using
zypper or the graphical Software Update for all software installation
allows for insight into the current inventory of installed software on the system.
|
Rule
Ensure gpgcheck Enabled In Main zypper Configuration
[ref] | 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
| Rationale: | 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). | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated | Identifiers: | CCE-83290-7 | References: | cis-csc | 11, 2, 3, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02 | cui | 3.4.8 | disa | CCI-001749 | hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i) | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4 | nist | CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b) | nist-csf | PR.DS-6, PR.DS-8, PR.IP-1 | ospp | FPT_TUD_EXT.1, FPT_TUD_EXT.2 | pcidss | Req-6.2 | os-srg | SRG-OS-000366-GPOS-00153 | stigid | SLES-15-010430 | cis | 1.2.3 | anssi | R59 | pcidss4 | 6.3.3, 6.3 | stigref | SV-234852r986469_rule |
| |
|
Rule
Ensure gpgcheck Enabled for All zypper Package Repositories
[ref] | To ensure signature checking is not disabled for
any repos, remove any lines from files in /etc/yum.repos.d of the form:
gpgcheck=0
| Rationale: | 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)." | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_gpgcheck_never_disabled | Identifiers: | CCE-85797-9 | References: | cis-csc | 11, 2, 3, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02 | cui | 3.4.8 | disa | CCI-001749 | hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i) | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4 | nist | CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b) | nist-csf | PR.DS-6, PR.DS-8, PR.IP-1 | ospp | FPT_TUD_EXT.1, FPT_TUD_EXT.2 | pcidss | Req-6.2 | os-srg | SRG-OS-000366-GPOS-00153 | cis | 1.2.3 | anssi | R59 | pcidss4 | 6.3.3, 6.3 |
| |
|
Rule
Ensure SUSE GPG Key Installed
[ref] | To ensure the system can cryptographically verify base software packages
come from SUSE (and to connect to the SUSE to receive them),
the SUSE GPG key must properly be installed. To install the SUSE GPG
key, run:
$ sudo zypper install suse-build-key
If the system is not connected to the Internet or an RHN Satellite, then
install the SUSE GPG key from trusted media such as the SUSE
installation CD-ROM or DVD. Assuming the disc is mounted in
/media/cdrom , use the following command as the root user to import
it into the keyring:
$ sudo rpm --import /media/cdrom/content.key or
$ sudo rpm --import /media/cdrom/repodata/repomd.xml.key
Alternatively, the key may be pre-loaded during the SUSE installation. In
such cases, one can use the repository cache files to install the key,
for example by running the following command:
sudo rpm --import /var/cache/zypp/raw/Basesystem_Module_15_SP2_x86_64:SLE-Module-Basesystem15-SP2-Pool/repodata/repomd.xml.key
| Rationale: | Changes to 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.
The SUSE GPG key is necessary to cryptographically verify packages are
from SUSE. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_suse_gpgkey_installed | Identifiers: | CCE-85796-1 | References: | cis-csc | 11, 2, 3, 9 | cjis | 5.10.4.1 | cobit5 | APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02 | cui | 3.4.8 | disa | CCI-001749 | hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i) | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4 | isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6 | iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4 | nerc-cip | CIP-003-8 R4.2, CIP-003-8 R6, CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1 | nist | CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a) | nist-csf | PR.DS-6, PR.DS-8, PR.IP-1 | ospp | FPT_TUD_EXT.1, FPT_TUD_EXT.2 | pcidss | Req-6.2 | os-srg | SRG-OS-000366-GPOS-00153 | pcidss4 | 6.3.3, 6.3 |
| |
|
Rule
Ensure Software Patches Installed
[ref] |
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. Warning:
The OVAL feed of SUSE Linux Enterprise 15 is not a XML file, which may not be understood by all scanners. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_security_patches_up_to_date | Identifiers: | CCE-83261-8 | References: | cis-csc | 18, 20, 4 | cjis | 5.10.4.1 | cobit5 | APO12.01, APO12.02, APO12.03, APO12.04, BAI03.10, DSS05.01, DSS05.02 | disa | CCI-000366, CCI-001227 | isa-62443-2009 | 4.2.3, 4.2.3.12, 4.2.3.7, 4.2.3.9 | iso27001-2013 | A.12.6.1, A.14.2.3, A.16.1.3, A.18.2.2, A.18.2.3 | nist | SI-2(5), SI-2(c), CM-6(a) | nist-csf | ID.RA-1, PR.IP-12 | ospp | FMT_MOF_EXT.1 | pcidss | Req-6.2 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-010010 | cis | 1.9 | anssi | R61 | pcidss4 | 6.3.3, 6.3 | stigref | SV-234802r991589_rule |
| |
|
Group
Account and Access Control
Group contains 12 groups and 39 rules |
[ref]
In traditional Unix security, if an attacker gains
shell access to a certain login account, they can perform any action
or access any file to which that account has access. Therefore,
making it more difficult for unauthorized people to gain shell
access to accounts, particularly to privileged accounts, is a
necessary part of securing a system. This section introduces
mechanisms for restricting access to accounts under
SUSE Linux Enterprise 15. |
Group
Warning Banners for System Accesses
Group contains 3 rules |
[ref]
Each system should expose as little information about
itself as possible.
System banners, which are typically displayed just before a
login prompt, give out information about the service or the host's
operating system. This might include the distribution name and the
system kernel version, and the particular version of a network
service. This information can assist intruders in gaining access to
the system as it can reveal whether the system is running
vulnerable software. Most network services can be configured to
limit what information is displayed.
Many organizations implement security policies that require a
system banner provide notice of the system's ownership, provide
warning to unauthorized users, and remind authorized users of their
consent to monitoring. |
Rule
Verify Group Ownership of System Login Banner for Remote Connections
[ref] |
To properly set the group owner of /etc/issue.net , run the command:
$ sudo chgrp root /etc/issue.net
| Rationale: | 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.
Proper group ownership will ensure that only root user can modify the banner. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_issue_net | Identifiers: | CCE-91358-2 | References: | | |
|
Rule
Verify ownership of System Login Banner for Remote Connections
[ref] |
To properly set the owner of /etc/issue.net , run the command:
$ sudo chown root /etc/issue.net
| Rationale: | 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.
Proper ownership will ensure that only root user can modify the banner. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_issue_net | Identifiers: | CCE-91359-0 | References: | | |
|
Rule
Verify permissions on System Login Banner for Remote Connections
[ref] |
To properly set the permissions of /etc/issue.net , run the command:
$ sudo chmod 0644 /etc/issue.net
| Rationale: | 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.
Proper permissions will ensure that only root user can modify the banner. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_issue_net | Identifiers: | CCE-91357-4 | References: | | |
|
Group
Protect Accounts by Configuring PAM
Group contains 4 groups and 12 rules |
[ref]
PAM, or Pluggable Authentication Modules, is a system
which implements modular authentication for Linux programs. PAM provides
a flexible and configurable architecture for authentication, and it should be configured
to minimize exposure to unnecessary risk. This section contains
guidance on how to accomplish that.
PAM is implemented as a set of shared objects which are
loaded and invoked whenever an application wishes to authenticate a
user. Typically, the application must be running as root in order
to take advantage of PAM, because PAM's modules often need to be able
to access sensitive stores of account information, such as /etc/shadow.
Traditional privileged network listeners
(e.g. sshd) or SUID programs (e.g. sudo) already meet this
requirement. An SUID root application, userhelper, is provided so
that programs which are not SUID or privileged themselves can still
take advantage of PAM.
PAM looks in the directory /etc/pam.d for
application-specific configuration information. For instance, if
the program login attempts to authenticate a user, then PAM's
libraries follow the instructions in the file /etc/pam.d/login
to determine what actions should be taken.
One very important file in /etc/pam.d is
/etc/pam.d/system-auth . This file, which is included by
many other PAM configuration files, defines 'default' system authentication
measures. Modifying this file is a good way to make far-reaching
authentication changes, for instance when implementing a
centralized authentication service. Warning:
Be careful when making changes to PAM's configuration files.
The syntax for these files is complex, and modifications can
have unexpected consequences. The default configurations shipped
with applications should be sufficient for most users. |
Group
Set Lockouts for Failed Password Attempts
Group contains 3 rules |
[ref]
The pam_faillock PAM module provides the capability to
lock out user accounts after a number of failed login attempts. Its
documentation is available in
/usr/share/doc/pam-VERSION/txts/README.pam_faillock .
Warning:
Locking out user accounts presents the
risk of a denial-of-service attack. The lockout policy
must weigh whether the risk of such a
denial-of-service attack outweighs the benefits of thwarting
password guessing attacks. |
Rule
Limit Password Reuse
[ref] | Do not allow users to reuse recent passwords. This can be accomplished by using the
remember option for the pam_unix or pam_pwhistory PAM modules. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report. Warning:
Newer versions of authselect contain an authselect feature to easily and properly
enable pam_pwhistory.so module. If this feature is not yet available in your
system, an authselect custom profile must be used to avoid integrity issues in PAM files. | Rationale: | Preventing re-use of previous passwords helps ensure that a compromised password is not
re-used by a user. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_unix_remember | Identifiers: | CCE-85678-1 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.6.2.1.1 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.8 | disa | CCI-000200 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(f), IA-5(1)(e) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.5 | os-srg | SRG-OS-000077-GPOS-00045 | anssi | R31 | pcidss4 | 8.3.7, 8.3 |
| |
|
Rule
Set Deny For Failed Password Attempts
[ref] | The SUSE Linux Enterprise 15 operating system must lock an account after - at most - 10
consecutive invalid access attempts. | Rationale: | By limiting the number of failed logon attempts, the risk of unauthorized
system access via user password guessing, otherwise known as brute-force
attacks, is reduced. Limits are imposed by locking the account.
To configure the operating system to lock an account after three
unsuccessful consecutive access attempts using pam_tally2.so ,
modify the content of both /etc/pam.d/login and
/etc/pam.d/common-account as follows:
| Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_passwords_pam_tally2 | Identifiers: | CCE-85554-4 | References: | | |
|
Rule
Set Lockout Time for Failed Password Attempts using pam_tally2
[ref] | This rule configures the system to lock out accounts during a specified time period after a
number of incorrect login attempts using pam_tally2.so . | Rationale: | By limiting the number of failed logon attempts, the risk of unauthorized system access via
user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking
the account. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_passwords_pam_tally2_unlock_time | Identifiers: | CCE-91282-4 | References: | cis-csc | 1, 12, 15, 16 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | disa | CCI-002238, CCI-000044 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | ism | 0421, 0422, 0431, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | CM-6(a), AC-7(b), IA-5(c) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | pcidss | Req-8.1.7 | os-srg | SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005 | cis | 5.3.2 | anssi | R31 | pcidss4 | 8.3.4, 8.3 |
| |
|
Group
Set Password Quality Requirements
Group contains 1 group and 4 rules |
[ref]
The default pam_pwquality PAM module provides strength
checking for passwords. It performs a number of checks, such as
making sure passwords are not similar to dictionary words, are of
at least a certain length, are not the previous password reversed,
and are not simply a change of case from the previous password. It
can also require passwords to be in certain character classes. The
pam_pwquality module is the preferred way of configuring
password requirements.
The man pages pam_pwquality(8)
provide information on the capabilities and configuration of
each. |
Group
Set Password Quality Requirements, if using
pam_cracklib
Group contains 4 rules |
[ref]
The pam_cracklib PAM module can be configured to meet
requirements for a variety of policies.
For example, to configure pam_cracklib to require at least one uppercase
character, lowercase character, digit, and other (special)
character, locate the following line in /etc/pam.d/system-auth :
password requisite pam_cracklib.so try_first_pass retry=3
and then alter it to read:
password required pam_cracklib.so try_first_pass retry=3 maxrepeat=3 minlen=14 dcredit=-1 ucredit=-1 ocredit=-1 lcredit=-1 difok=4
If no such line exists, add one as the first line of the password section in /etc/pam.d/system-auth .
The arguments can be modified to ensure compliance with
your organization's security policy. Discussion of each parameter follows. Warning:
Note that the password quality requirements are not enforced for the
root account for some reason. |
Rule
Set Password Strength Minimum Digit Characters
[ref] | 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. | Rationale: | Requiring digits makes password guessing attacks more difficult by ensuring
a larger search space. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_dcredit | Identifiers: | CCE-85564-3 | References: | | |
|
Rule
Set Password Strength Minimum Lowercase Characters
[ref] | 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. | Rationale: | Requiring a minimum number of lowercase characters makes password guessing
attacks more difficult by ensuring a larger search space. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_lcredit | Identifiers: | CCE-85676-5 | References: | | |
|
Rule
Set Password Minimum Length
[ref] | The pam_cracklib module's minlen parameter controls requirements for
minimum characters required in a password. Add minlen=12
to set minimum password length requirements. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_minlen | Identifiers: | CCE-85573-4 | References: | | |
|
Rule
Set Password Retry Limit
[ref] | 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 . | Rationale: | To reduce opportunities for successful guesses and brute-force attacks. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_cracklib_accounts_password_pam_retry | Identifiers: | CCE-85575-9 | References: | | |
|
Group
Set Password Hashing Algorithm
Group contains 4 rules |
[ref]
The system's default algorithm for storing password hashes in
/etc/shadow is SHA-512. This can be configured in several
locations. |
Rule
Set PAM's Common Authentication Hashing Algorithm
[ref] | The PAM system service can be configured to only store encrypted
representations of passwords. In
/etc/pam.d/common-auth ,
the
auth section of the file controls which PAM modules execute
during a password change. Set the pam_unix.so module in the
auth section to include the argument sha512 , as shown
below:
auth required pam_unix.so sha512 other arguments...
This will help ensure when local users change their authentication method,
hashes for the new authentications will be generated using the SHA-512
algorithm. This is the default. | Rationale: | Unapproved mechanisms used for authentication to the cryptographic module
are not verified and therefore cannot be relied on to provide
confidentiality or integrity, and data may be compromised.
This setting ensures user and group account administration utilities are
configured to store only encrypted representations of passwords.
Additionally, the crypt_style configuration option ensures the use
of a strong hashing algorithm that makes password cracking attacks more
difficult. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_commonauth | Identifiers: | CCE-85754-0 | References: | | |
|
Rule
Set Password Hashing Algorithm in /etc/libuser.conf
[ref] | In /etc/libuser.conf , add or correct the following line in its [defaults]
section to ensure the system will use the sha512
algorithm for password hashing:
crypt_style = sha512
| Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_libuserconf | Identifiers: | CCE-85798-7 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.6.2.2 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.13.11 | disa | CCI-000196 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | ism | 0418, 1055, 1402 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(c), IA-5(1)(c), CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.1 | os-srg | SRG-OS-000073-GPOS-00041 | pcidss4 | 8.3.2, 8.3 |
| |
|
Rule
Set Password Hashing Algorithm in /etc/login.defs
[ref] | In /etc/login.defs , add or update the following line to ensure the system will use
SHA512 as the hashing algorithm:
ENCRYPT_METHOD SHA512
| Rationale: | Passwords need to be protected at all times, and encryption is the standard method for
protecting passwords. If passwords are not encrypted, they can be plainly read
(i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm
are no more protected than if they are kept in plain text.
Using a stronger hashing algorithm makes password cracking attacks more difficult. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs | Identifiers: | CCE-83279-0 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.6.2.2 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.13.11 | disa | CCI-000196 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | ism | 0418, 1055, 1402 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(c), IA-5(1)(c), CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.1 | os-srg | SRG-OS-000073-GPOS-00041 | stigid | SLES-15-010260 | cis | 5.4.1.1 | pcidss4 | 8.3.2, 8.3 | stigref | SV-234825r971535_rule |
| |
|
Rule
Set PAM''s Password Hashing Algorithm
[ref] | 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. Warning:
The hashing algorithms to be used with pam_unix.so are defined with independent module
options. There are at least 7 possible algorithms and likely more algorithms will be
introduced along the time. Due the the number of options and its possible combinations,
the use of multiple hashing algorithm options may bring unexpected behaviors to the
system. For this reason the check will pass only when one hashing algorithm option is
defined and is aligned to the "var_password_hashing_algorithm_pam" variable. The
remediation will ensure the correct option and remove any other extra hashing algorithm
option. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_systemauth | Identifiers: | CCE-85565-0 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.6.2.2 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.13.11 | disa | CCI-000196, CCI-000803, CCI-004062 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | ism | 0418, 1055, 1402 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(c), IA-5(1)(c), CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.1 | os-srg | SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061 | stigid | SLES-15-020170 | anssi | R68 | pcidss4 | 8.3.2, 8.3 | stigref | SV-234886r986482_rule |
| |
|
Rule
Ensure PAM Displays Last Logon/Access Notification
[ref] | 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/login
to include showfailed option, such as:
session optional pam_lastlog.so showfailed
And make sure that the silent option is not set for this specific line. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report. Warning:
authselect contains an authselect feature to easily and properly enable Last Logon
notifications with pam_lastlog.so module. If a custom profile was created and used
in the system before this authselect feature was available, the new feature can't be used
with this custom profile and the remediation will fail. In this case, the custom profile
should be recreated or manually updated. | Rationale: | 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. | Severity: | low | Rule ID: | xccdf_org.ssgproject.content_rule_display_login_attempts | Identifiers: | CCE-85560-1 | References: | cis-csc | 1, 12, 15, 16 | cjis | 5.5.2 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | disa | CCI-000052 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | ism | 0582, 0584, 05885, 0586, 0846, 0957 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nist | AC-9, AC-9(1) | nist-csf | PR.AC-7 | pcidss | Req-10.2.4 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-020080 | pcidss4 | 10.2.1.4, 10.2.1, 10.2 | stigref | SV-234873r991589_rule |
| |
|
Group
Protect Accounts by Restricting Password-Based Login
Group contains 4 groups and 23 rules |
[ref]
Conventionally, Unix shell accounts are accessed by
providing a username and password to a login program, which tests
these values for correctness using the /etc/passwd and
/etc/shadow files. Password-based login is vulnerable to
guessing of weak passwords, and to sniffing and man-in-the-middle
attacks against passwords entered over a network or at an insecure
console. Therefore, mechanisms for accessing accounts by entering
usernames and passwords should be restricted to those which are
operationally necessary. |
Group
Set Account Expiration Parameters
Group contains 3 rules |
[ref]
Accounts can be configured to be automatically disabled
after a certain time period,
meaning that they will require administrator interaction to become usable again.
Expiration of accounts after inactivity can be set for all accounts by default
and also on a per-account basis, such as for accounts that are known to be temporary.
To configure automatic expiration of an account following
the expiration of its password (that is, after the password has expired and not been changed),
run the following command, substituting NUM_DAYS and USER appropriately:
$ sudo chage -I NUM_DAYS USER
Accounts, such as temporary accounts, can also be configured to expire on an explicitly-set date with the
-E option.
The file /etc/default/useradd controls
default settings for all newly-created accounts created with the system's
normal command line utilities. Warning:
This will only apply to newly created accounts |
Rule
Set Account Expiration Following Inactivity
[ref] | 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=90
If a password is currently on the verge of expiration, then
90
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 90 day(s) could
elapse until the account would be automatically disabled. See the
useradd man page for more information. | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_account_disable_post_pw_expiration | Identifiers: | CCE-85558-5 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8 | cjis | 5.6.2.1.1 | cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.6 | disa | CCI-000017, CCI-000795 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2 | iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3 | nist | IA-4(e), AC-2(3), CM-6(a) | nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7 | pcidss | Req-8.1.4 | os-srg | SRG-OS-000118-GPOS-00060 | stigid | SLES-15-020050 | cis | 5.4.1.5 | pcidss4 | 8.2.6, 8.2 | stigref | SV-234871r986475_rule |
| |
|
Rule
Ensure All Accounts on the System Have Unique Names
[ref] | Ensure accounts on the system have unique names.
To ensure all accounts have unique names, run the following command:
$ sudo getent passwd | awk -F: '{ print $1}' | uniq -d
If a username is returned, change or delete the username. | Rationale: | Unique usernames allow for accountability on the system. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_account_unique_name | Identifiers: | CCE-85845-6 | References: | | |
|
Rule
Ensure shadow Group is Empty
[ref] | The shadow group allows system programs which require access the ability
to read the /etc/shadow file. No users should be assigned to the shadow group. Warning:
This rule remediation will ensure the group membership is empty in /etc/group. To avoid any
disruption the remediation won't change the primary group of users in /etc/passwd if any
user has the shadow GID as primary group. | Rationale: | Any users assigned to the shadow group would be granted read access to the
/etc/shadow file. If attackers can gain read access to the /etc/shadow file,
they can easily run a password cracking program against the hashed passwords
to break them. Other security information that is stored in the /etc/shadow
file (such as expiration) could also be useful to subvert additional user
accounts. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_shadow_group_empty | Identifiers: | CCE-91344-2 | References: | | |
|
Group
Set Password Expiration Parameters
Group contains 5 rules |
[ref]
The file /etc/login.defs controls several
password-related settings. Programs such as passwd ,
su , and
login consult /etc/login.defs to determine
behavior with regard to password aging, expiration warnings,
and length. See the man page login.defs(5) for more information.
Users should be forced to change their passwords, in order to
decrease the utility of compromised passwords. However, the need to
change passwords often should be balanced against the risk that
users will reuse or write down passwords if forced to change them
too often. Forcing password changes every 90-360 days, depending on
the environment, is recommended. Set the appropriate value as
PASS_MAX_DAYS and apply it to existing accounts with the
-M flag.
The PASS_MIN_DAYS ( -m ) setting prevents password
changes for 7 days after the first change, to discourage password
cycling. If you use this setting, train users to contact an administrator
for an emergency password change in case a new password becomes
compromised. The PASS_WARN_AGE ( -W ) setting gives
users 7 days of warnings at login time that their passwords are about to expire.
For example, for each existing human user USER, expiration parameters
could be adjusted to a 180 day maximum password age, 7 day minimum password
age, and 7 day warning period with the following command:
$ sudo chage -M 180 -m 7 -W 7 USER
|
Rule
Set Password Maximum Age
[ref] | To specify password maximum age for new accounts,
edit the file /etc/login.defs
and add or correct the following line:
PASS_MAX_DAYS 90
A value of 180 days is sufficient for many environments.
The DoD requirement is 60.
The profile requirement is 90 . | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_maximum_age_login_defs | Identifiers: | CCE-85570-0 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.6.2.1 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.6 | disa | CCI-000199, CCI-004066 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | ism | 0418, 1055, 1402 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(f), IA-5(1)(d), CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.4 | os-srg | SRG-OS-000076-GPOS-00044 | stigid | SLES-15-020220 | cis | 5.4.1.2 | pcidss4 | 8.3.9, 8.3 | stigref | SV-234891r986490_rule |
| |
|
Rule
Set Existing Passwords Maximum Age
[ref] | Configure non-compliant accounts to enforce a 90-day maximum password lifetime
restriction by running the following command:
$ sudo chage -M 90
USER
| Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_set_max_life_existing | Identifiers: | CCE-85571-8 | References: | | |
|
Rule
Set Existing Passwords Warning Age
[ref] | To configure how many days prior to password expiration that a warning will be issued to
users, run the command:
$ sudo chage --warndays 7
USER
The DoD requirement is 7, and CIS recommendation is no less than 7 days.
This profile requirement is 7 . | Rationale: | Providing an advance warning that a password will be expiring gives users
time to think of a secure password. Users caught unaware may choose a simple
password or write it down where it may be discovered. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_set_warn_age_existing | Identifiers: | CCE-92479-5 | References: | | |
|
Rule
Set Password Warning Age
[ref] | To specify how many days prior to password
expiration that a warning will be issued to users,
edit the file /etc/login.defs and add or correct
the following line:
PASS_WARN_AGE 7
The DoD requirement is 7.
The profile requirement is 7 . | Rationale: | Setting the password warning age enables users to
make the change at a practical time. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_warn_age_login_defs | Identifiers: | CCE-91335-0 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8 | cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.8 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2 | ism | 0418, 1055, 1402 | iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nist | IA-5(f), IA-5(1)(d), CM-6(a) | nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.4 | cis | 5.4.1.4 | pcidss4 | 8.3.9, 8.3 |
| |
|
Rule
Set existing passwords a period of inactivity before they been locked
[ref] | Configure user accounts that have been inactive for over a given period of time
to be automatically disabled by running the following command:
$ sudo chage --inactive 30USER
| Rationale: | Inactive accounts pose a threat to system security since the users are not logging in to
notice failed login attempts or other anomalies. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_set_post_pw_existing | Identifiers: | CCE-92480-3 | References: | cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.6 | disa | CCI-000017, CCI-000795, CCI-003627, CCI-003628 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2 | iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3 | nist | IA-4(e), AC-2(3), CM-6(a) | nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7 | pcidss | Req-8.1.4 | os-srg | SRG-OS-000118-GPOS-00060 | cis | 5.4.1.5 | pcidss4 | 8.2.6, 8.2 |
| |
|
Group
Verify Proper Storage and Existence of Password
Hashes
Group contains 5 rules |
[ref]
By default, password hashes for local accounts are stored
in the second field (colon-separated) in
/etc/shadow . This file should be readable only by
processes running with root credentials, preventing users from
casually accessing others' password hashes and attempting
to crack them.
However, it remains possible to misconfigure the system
and store password hashes
in world-readable files such as /etc/passwd , or
to even store passwords themselves in plaintext on the system.
Using system-provided tools for password change/creation
should allow administrators to avoid such misconfiguration. |
Rule
Verify All Account Password Hashes are Shadowed
[ref] | If any password hashes are stored in /etc/passwd (in the second field,
instead of an x or * ), the cause of this misconfiguration should be
investigated. The account should have its password reset and the hash should be
properly stored, or the account should be deleted entirely. | Rationale: | The hashes for all user account passwords should be stored in
the file /etc/shadow and never in /etc/passwd ,
which is readable by all users. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_all_shadowed | Identifiers: | CCE-85846-4 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.5.2 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.5.10 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | ism | 1410 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nist | IA-5(h), CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.2.1 | cis | 6.2.1 | pcidss4 | 8.3.2, 8.3 |
| |
|
Rule
Ensure all users last password change date is in the past
[ref] | All users should have a password change date in the past. Warning:
Automatic remediation is not available, in order to avoid any system disruption. | Rationale: | If a user recorded password change date is in the future then they could
bypass any set password expiration. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_last_change_is_in_past | Identifiers: | CCE-92504-0 | References: | | |
|
Rule
All GIDs referenced in /etc/passwd must be defined in /etc/group
[ref] | Add a group to the system for each GID referenced without a corresponding group. | Rationale: | If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group
with the Group Identifier (GID) is subsequently created, the user may have unintended rights to
any files associated with the group. | Severity: | low | Rule ID: | xccdf_org.ssgproject.content_rule_gid_passwd_group_same | Identifiers: | CCE-85847-2 | References: | cis-csc | 1, 12, 15, 16, 5 | cjis | 5.5.2 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | disa | CCI-000764 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3 | nist | IA-2, CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | pcidss | Req-8.5.a | os-srg | SRG-OS-000104-GPOS-00051 | cis | 6.2.13 | pcidss4 | 8.2.2, 8.2 |
| |
|
Rule
Prevent Login to Accounts With Empty Password
[ref] | 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. Warning:
If the system relies on authselect tool to manage PAM settings, the remediation
will also use authselect tool. However, if any manual modification was made in
PAM files, the authselect integrity check will fail and the remediation will be
aborted in order to preserve intentional changes. In this case, an informative message will
be shown in the remediation report.
Note that this rule is not applicable for systems running within a
container. Having user with empty password within a container is not
considered a risk, because it should not be possible to directly login into
a container anyway. | Rationale: | 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. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_no_empty_passwords | Identifiers: | CCE-85576-7 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5 | cjis | 5.5.2 | cobit5 | APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10 | cui | 3.1.1, 3.1.5 | disa | CCI-000366 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nist | IA-5(1)(a), IA-5(c), CM-6(a) | nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5 | ospp | FIA_UAU.1 | pcidss | Req-8.2.3 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-020300 | pcidss4 | 8.3.1, 8.3 | stigref | SV-234898r991589_rule |
| |
|
Rule
Ensure There Are No Accounts With Blank or Null Passwords
[ref] | 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]
Warning:
Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway. | Rationale: | 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. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow | Identifiers: | CCE-91155-2 | References: | | |
|
Group
Restrict Root Logins
Group contains 7 rules |
[ref]
Direct root logins should be allowed only for emergency use.
In normal situations, the administrator should access the system
via a unique unprivileged account, and then use su or sudo to execute
privileged commands. Discouraging administrators from accessing the
root account directly ensures an audit trail in organizations with
multiple administrators. Locking down the channels through which
root can connect directly also reduces opportunities for
password-guessing against the root account. The login program
uses the file /etc/securetty to determine which interfaces
should allow root logins.
The virtual devices /dev/console
and /dev/tty* represent the system consoles (accessible via
the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default
installation). The default securetty file also contains /dev/vc/* .
These are likely to be deprecated in most environments, but may be retained
for compatibility. Root should also be prohibited from connecting
via network protocols. Other sections of this document
include guidance describing how to prevent root from logging in via SSH. |
Rule
Verify Only Root Has UID 0
[ref] | 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. | Rationale: | 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. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero | Identifiers: | CCE-85664-1 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5 | cobit5 | APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10 | cui | 3.1.1, 3.1.5 | disa | CCI-000366 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3 | nist | CM-6(b), CM-6.1(iv) | nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5 | pcidss | Req-8.5 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-020100 | cis | 6.2.3 | pcidss4 | 8.2.1, 8.2 | stigref | SV-234876r991589_rule |
| |
|
Rule
Verify Root Has A Primary GID 0
[ref] | The root user should have a primary group of 0. | Rationale: | To help ensure that root-owned files are not inadvertently exposed to other users. | Severity: | high | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_root_gid_zero | Identifiers: | CCE-91289-9 | References: | | |
|
Rule
Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty
[ref] | Ensure that the group sugroup referenced by
var_pam_wheel_group_for_su variable and used as value for the pam_wheel.so
group option exists and has no members. This empty group used by
pam_wheel.so in /etc/pam.d/su ensures that no user can run commands with
altered privileges through the su command. Warning:
Note that this rule just ensures the group exists and has no members. This rule does not
configure pam_wheel.so module. The pam_wheel.so module configuration is
accomplished by use_pam_wheel_group_for_su rule. | Rationale: | The su program allows to run commands with a substitute user and group ID.
It is commonly used to run commands as the root user.
Limiting access to such command is considered a good security practice. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_pam_wheel_group_empty | Identifiers: | CCE-92528-9 | References: | | |
|
Rule
Direct root Logins Not Allowed
[ref] | To further limit access to the root account, administrators
can disable root logins at the console by editing the /etc/securetty file.
This file lists all devices the root user is allowed to login to. If the file does
not exist at all, the root user can login through any communication device on the
system, whether via the console or via a raw network interface. This is dangerous
as user can login to the system as root via Telnet, which sends the password in
plain text over the network. By default, SUSE Linux Enterprise 15's
/etc/securetty file only allows the root user to login at the console
physically attached to the system. To prevent root from logging in, remove the
contents of this file. To prevent direct root logins, remove the contents of this
file by typing the following command:
$ sudo echo > /etc/securetty
Warning:
This rule only checks the /etc/securetty file existence and its content.
If you need to restrict user access using the /etc/securetty file, make sure
the pam_securetty.so PAM module is properly enabled in relevant PAM files. | Rationale: | Disabling direct root logins ensures proper accountability and multifactor
authentication to privileged accounts. Users will first login, then escalate
to privileged (root) access via su / sudo. This is required for FISMA Low
and FISMA Moderate systems. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_no_direct_root_logins | Identifiers: | CCE-91427-5 | References: | cis-csc | 1, 12, 15, 16, 5 | cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10 | cui | 3.1.1, 3.1.6 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1 | iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3 | nist | IA-2, CM-6(a) | nist-csf | PR.AC-1, PR.AC-6, PR.AC-7 | cis | 5.5 | anssi | R33 | pcidss4 | 8.6.1, 8.6 |
| |
|
Rule
Ensure that System Accounts Do Not Run a Shell Upon Login
[ref] | 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
Warning:
Do not perform the steps in this section on the root account. Doing so might cause the
system to become inaccessible. | Rationale: | Ensuring shells are not given to system accounts upon login makes it more difficult for
attackers to make use of system accounts. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_no_shelllogin_for_systemaccounts | Identifiers: | CCE-85672-4 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8 | cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS06.03 | disa | CCI-000366 | isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4 | isa-62443-2013 | SR 1.1, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2 | ism | 1491 | iso27001-2013 | A.12.4.1, A.12.4.3, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5 | nist | AC-6, CM-6(a), CM-6(b), CM-6.1(iv) | nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-020091 | cis | 5.4.2 | pcidss4 | 8.2.2, 8.2 | stigref | SV-234875r991589_rule |
| |
|
Rule
Restrict Virtual Console Root Logins
[ref] | To restrict root logins through the (deprecated) virtual console devices,
ensure lines of this form do not appear in /etc/securetty :
vc/1
vc/2
vc/3
vc/4
| Rationale: | Preventing direct root login to virtual console devices
helps ensure accountability for actions taken on the system
using the root account. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_securetty_root_login_console_only | Identifiers: | CCE-91430-9 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | cui | 3.1.1, 3.1.5 | disa | CCI-000770 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | nist | AC-6, CM-6(a) | nist-csf | PR.AC-4, PR.DS-5 | os-srg | SRG-OS-000324-GPOS-00125 | cis | 5.5 | pcidss4 | 8.6.1, 8.6 |
| |
|
Rule
Enforce Usage of pam_wheel with Group Parameter for su Authentication
[ref] | To ensure that only users who are members of the group set in the group option of
pam_wheel.so module can run commands with altered privileges through the su
command, make sure that the following line exists in the file /etc/pam.d/su :
auth required pam_wheel.so use_uid group=sugroup
Warning:
Note that ensure_pam_wheel_group_empty rule complements this requirement by
ensuring the referenced group exists and has no members. | Rationale: | The su program allows to run commands with a substitute user and group ID.
It is commonly used to run commands as the root user.
Limiting access to such command is considered a good security practice. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_use_pam_wheel_group_for_su | Identifiers: | CCE-92522-2 | References: | | |
|
Rule
Ensure All Accounts on the System Have Unique User IDs
[ref] | Change user IDs (UIDs), or delete accounts, so each has a unique name. Warning:
Automatic remediation of this control is not available due to unique requirements of each
system. | Rationale: | To assure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_account_unique_id | Identifiers: | CCE-83277-4 | References: | | |
|
Rule
Ensure All Groups on the System Have Unique Group ID
[ref] | Change the group name or delete groups, so each has a unique id. Warning:
Automatic remediation of this control is not available due to the unique requirements of each system. | Rationale: | To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_group_unique_id | Identifiers: | CCE-91339-2 | References: | | |
|
Rule
Ensure All Groups on the System Have Unique Group Names
[ref] | Change the group name or delete groups, so each has a unique name. Warning:
Automatic remediation of this control is not available due to the unique requirements of each system. | Rationale: | To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_group_unique_name | Identifiers: | CCE-91340-0 | References: | | |
|
Group
Secure Session Configuration Files for Login Accounts
Group contains 1 rule |
[ref]
When a user logs into a Unix account, the system
configures the user's session by reading a number of files. Many of
these files are located in the user's home directory, and may have
weak permissions as a result of user error or misconfiguration. If
an attacker can modify or even read certain types of account
configuration information, they can often gain full access to the
affected user's account. Therefore, it is important to test and
correct configuration file permissions for interactive accounts,
particularly those of privileged users such as root or system
administrators. |
Rule
Set Interactive Session Timeout
[ref] | Setting the TMOUT option in /etc/profile ensures that
all user sessions will terminate based on inactivity.
The value of TMOUT should be exported and read only.
The TMOUT
setting in /etc/profile.d/autologout.sh should read as follows:
TMOUT=900
readonly TMOUT
export TMOUT | Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_accounts_tmout | Identifiers: | CCE-83269-1 | References: | cis-csc | 1, 12, 15, 16 | cobit5 | DSS05.04, DSS05.10, DSS06.10 | cui | 3.1.11 | disa | CCI-000057, CCI-001133, CCI-002361 | isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9 | iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3 | nerc-cip | CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3 | nist | AC-12, SC-10, AC-2(5), CM-6(a) | nist-csf | PR.AC-7 | ospp | FMT_MOF_EXT.1 | os-srg | SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010 | stigid | SLES-15-010130 | cis | 5.4.4 | anssi | R32 | pcidss4 | 8.6.1, 8.6 | stigref | SV-234813r958402_rule |
| |
|
Group
GRUB2 bootloader configuration
Group contains 1 group and 3 rules |
[ref]
During the boot process, the boot loader is
responsible for starting the execution of the kernel and passing
options to it. The boot loader allows for the selection of
different kernels - possibly on different partitions or media.
The default SUSE Linux Enterprise 15 boot loader for x86 systems is called GRUB2.
Options it can pass to the kernel include single-user mode, which
provides root access without any authentication, and the ability to
disable SELinux. To prevent local users from modifying the boot
parameters and endangering security, protect the boot loader configuration
with a password and ensure its configuration file's permissions
are set properly. |
Group
Non-UEFI GRUB2 bootloader configuration
Group contains 3 rules |
[ref]
Non-UEFI GRUB2 bootloader configuration |
Rule
Verify /boot/grub2/grub.cfg Group Ownership
[ref] | The file /boot/grub2/grub.cfg should
be group-owned by the root group to prevent
destruction or modification of the file.
To properly set the group owner of /boot/grub2/grub.cfg , run the command:
$ sudo chgrp root /boot/grub2/grub.cfg
| Rationale: | The root group is a highly-privileged group. Furthermore, the group-owner of this
file should not have any access privileges anyway. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_grub2_cfg | Identifiers: | CCE-85849-8 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cjis | 5.5.2.2 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | cui | 3.4.5 | disa | CCI-000225 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nist | CM-6(a), AC-6(1) | nist-csf | PR.AC-4, PR.DS-5 | pcidss | Req-7.1 | os-srg | SRG-OS-000480-GPOS-00227 | cis | 1.5.2 | anssi | R29 | pcidss4 | 2.2.6, 2.2 |
| |
|
Rule
Verify /boot/grub2/grub.cfg User Ownership
[ref] | The file /boot/grub2/grub.cfg should
be owned by the root user to prevent destruction
or modification of the file.
To properly set the owner of /boot/grub2/grub.cfg , run the command:
$ sudo chown root /boot/grub2/grub.cfg
| Rationale: | Only root should be able to modify important boot parameters. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg | Identifiers: | CCE-85848-0 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cjis | 5.5.2.2 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | cui | 3.4.5 | disa | CCI-000225 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nist | CM-6(a), AC-6(1) | nist-csf | PR.AC-4, PR.DS-5 | pcidss | Req-7.1 | os-srg | SRG-OS-000480-GPOS-00227 | cis | 1.5.2 | anssi | R29 | pcidss4 | 2.2.6, 2.2 |
| |
|
Rule
Verify /boot/grub2/grub.cfg Permissions
[ref] | File permissions for /boot/grub2/grub.cfg should be set to 600.
To properly set the permissions of /boot/grub2/grub.cfg , run the command:
$ sudo chmod 600 /boot/grub2/grub.cfg
| Rationale: | Proper permissions ensure that only the root user can modify important boot
parameters. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg | Identifiers: | CCE-91426-7 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | cui | 3.4.5 | disa | CCI-000225 | hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii) | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nist | CM-6(a), AC-6(1) | nist-csf | PR.AC-4, PR.DS-5 | cis | 1.5.2 | anssi | R29 | pcidss4 | 2.2.6, 2.2 |
| |
|
Group
Configure Syslog
Group contains 2 groups and 5 rules |
[ref]
The syslog service has been the default Unix logging mechanism for
many years. It has a number of downsides, including inconsistent log format,
lack of authentication for received messages, and lack of authentication,
encryption, or reliable transport for messages sent over a network. However,
due to its long history, syslog is a de facto standard which is supported by
almost all Unix applications.
In SUSE Linux Enterprise 15, rsyslog has replaced ksyslogd as the
syslog daemon of choice, and it includes some additional security features
such as reliable, connection-oriented (i.e. TCP) transmission of logs, the
option to log to database formats, and the encryption of log data en route to
a central logging server.
This section discusses how to configure rsyslog for
best effect, and how to use tools provided with the system to maintain and
monitor logs. |
Group
Ensure Proper Configuration of Log Files
Group contains 3 rules |
[ref]
The file /etc/rsyslog.conf controls where log message are written.
These are controlled by lines called rules, which consist of a
selector and an action.
These rules are often customized depending on the role of the system, the
requirements of the environment, and whatever may enable
the administrator to most effectively make use of log data.
The default rules in SUSE Linux Enterprise 15 are:
*.info;mail.none;authpriv.none;cron.none /var/log/messages
authpriv.* /var/log/secure
mail.* -/var/log/maillog
cron.* /var/log/cron
*.emerg *
uucp,news.crit /var/log/spooler
local7.* /var/log/boot.log
See the man page rsyslog.conf(5) for more information.
Note that the rsyslog daemon can be configured to use a timestamp format that
some log processing programs may not understand. If this occurs,
edit the file /etc/rsyslog.conf and add or edit the following line:
$ ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
|
Rule
Ensure Log Files Are Owned By Appropriate Group
[ref] | The group-owner of all log files written by
rsyslog should be root .
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf and typically all appear in /var/log .
For each log file LOGFILE referenced in /etc/rsyslog.conf ,
run the following command to inspect the file's group owner:
$ ls -l LOGFILE
If the owner is not root ,
run the following command to
correct this:
$ sudo chgrp root LOGFILE
| Rationale: | The log files generated by rsyslog contain valuable information regarding system
configuration, user authentication, and other such information. Log files should be
protected from unauthorized access. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_groupownership | Identifiers: | CCE-85838-1 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | disa | CCI-001314 | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | ism | 0988, 1405 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | nist | CM-6(a), AC-6(1) | nist-csf | PR.AC-4, PR.DS-5 | pcidss | Req-10.5.1, Req-10.5.2 | cis | 4.2.1.3 | anssi | R71 | pcidss4 | 10.3.2, 10.3 |
| |
|
Rule
Ensure Log Files Are Owned By Appropriate User
[ref] | The owner of all log files written by
rsyslog should be
root .
These log files are determined by the second part of each Rule line in
/etc/rsyslog.conf and typically all appear in /var/log .
For each log file LOGFILE referenced in /etc/rsyslog.conf ,
run the following command to inspect the file's owner:
$ ls -l LOGFILE
If the owner is not
root ,
run the following command to
correct this:
$ sudo chown root LOGFILE
| Rationale: | The log files generated by rsyslog contain valuable information regarding system
configuration, user authentication, and other such information. Log files should be
protected from unauthorized access. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_ownership | Identifiers: | CCE-85839-9 | References: | cis-csc | 12, 13, 14, 15, 16, 18, 3, 5 | cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02 | disa | CCI-001314 | isa-62443-2009 | 4.3.3.7.3 | isa-62443-2013 | SR 2.1, SR 5.2 | ism | 0988, 1405 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | nist | CM-6(a), AC-6(1) | nist-csf | PR.AC-4, PR.DS-5 | pcidss | Req-10.5.1, Req-10.5.2 | cis | 4.2.1.3 | anssi | R71 | pcidss4 | 10.3.2, 10.3 |
| |
|
Rule
Ensure System Log Files Have Correct Permissions
[ref] | The file permissions for all log files written by rsyslog should
be set to 640, or more restrictive. These log files are determined by the
second part of each Rule line in /etc/rsyslog.conf and typically
all appear in /var/log . For each log file LOGFILE
referenced in /etc/rsyslog.conf , run the following command to
inspect the file's permissions:
$ ls -l LOGFILE
If the permissions are not 640 or more restrictive, run the following
command to correct this:
$ sudo chmod 640 LOGFILE
" | Rationale: | Log files can contain valuable information regarding system
configuration. If the system log files are not protected unauthorized
users could change the logged data, eliminating their forensic value. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_permissions | Identifiers: | CCE-85837-3 | References: | disa | CCI-001314 | ism | 0988, 1405 | nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2 | nist | CM-6(a), AC-6(1) | pcidss | Req-10.5.1, Req-10.5.2 | cis | 4.2.1.3 | anssi | R71 | pcidss4 | 10.3.1, 10.3 |
| |
|
Group
Ensure All Logs are Rotated by logrotate
Group contains 2 rules |
[ref]
Edit the file /etc/logrotate.d/syslog . Find the first
line, which should look like this (wrapped for clarity):
/var/log/messages /var/log/secure /var/log/maillog /var/log/spooler \
/var/log/boot.log /var/log/cron {
Edit this line so that it contains a one-space-separated
listing of each log file referenced in /etc/rsyslog.conf .
All logs in use on a system must be rotated regularly, or the
log files will consume disk space over time, eventually interfering
with system operation. The file /etc/logrotate.d/syslog is the
configuration file used by the logrotate program to maintain all
log files written by syslog . By default, it rotates logs weekly and
stores four archival copies of each log. These settings can be
modified by editing /etc/logrotate.conf , but the defaults are
sufficient for purposes of this guide.
Note that logrotate is run nightly by the cron job
/etc/cron.daily/logrotate . If particularly active logs need to be
rotated more often than once a day, some other mechanism must be
used. |
Rule
Ensure logrotate is Installed
[ref] | logrotate is installed by default. The logrotate package can be installed with the following command: $ sudo zypper install logrotate
| Rationale: | The logrotate package provides the logrotate services. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_package_logrotate_installed | Identifiers: | CCE-92561-0 | References: | cis-csc | 1, 14, 15, 16, 3, 5, 6 | cobit5 | APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01 | disa | CCI-000366 | isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4 | isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9 | iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1 | nist | CM-6(a) | nist-csf | PR.PT-1 | pcidss | Req-10.7 | cis | 4.2.4 | anssi | R71 | pcidss4 | 10.5.1, 10.5 |
| |
|
Rule
Enable logrotate Timer
[ref] |
The logrotate timer can be enabled with the following command:
$ sudo systemctl enable logrotate.timer
| Rationale: | Log files that are not properly rotated run the risk of growing so large
that they fill up the /var/log partition. Valuable logging information could be lost
if the /var/log partition becomes full. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_timer_logrotate_enabled | Identifiers: | CCE-92585-9 | References: | cis-csc | 1, 14, 15, 16, 3, 5, 6 | cobit5 | APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01 | disa | CCI-000366 | isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4 | isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9 | iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1 | nist | CM-6(a) | nist-csf | PR.PT-1 | pcidss | Req-10.7 | cis | 4.2.4 | anssi | R71 | pcidss4 | 10.5.1, 10.5 |
| |
|
Group
Network Configuration and Firewalls
Group contains 14 groups and 24 rules |
[ref]
Most systems must be connected to a network of some
sort, and this brings with it the substantial risk of network
attack. This section discusses the security impact of decisions
about networking which must be made when configuring a system.
This section also discusses firewalls, network access
controls, and other network security frameworks, which allow
system-level rules to be written that can limit an attackers' ability
to connect to your system. These rules can specify that network
traffic should be allowed or denied from certain IP addresses,
hosts, and networks. The rules can also specify which of the
system's network services are available to particular hosts or
networks. |
Group
firewalld
Group contains 2 groups and 4 rules |
[ref]
The dynamic firewall daemon firewalld provides a
dynamically managed firewall with support for network “zones” to assign
a level of trust to a network and its associated connections and interfaces.
It has support for IPv4 and IPv6 firewall settings. It supports Ethernet
bridges and has a separation of runtime and permanent configuration options.
It also has an interface for services or applications to add firewall rules
directly.
A graphical configuration tool, firewall-config , is used to configure
firewalld , which in turn uses iptables tool to communicate
with Netfilter in the kernel which implements packet filtering.
The firewall service provided by firewalld is dynamic rather than
static because changes to the configuration can be made at anytime and are
immediately implemented. There is no need to save or apply the changes. No
unintended disruption of existing network connections occurs as no part of
the firewall has to be reloaded. |
Group
Inspect and Activate Default firewalld Rules
Group contains 2 rules |
[ref]
Firewalls can be used to separate networks into different zones
based on the level of trust the user has decided to place on the devices and
traffic within that network. NetworkManager informs firewalld to which
zone an interface belongs. An interface's assigned zone can be changed by
NetworkManager or via the firewall-config tool.
The zone settings in /etc/firewalld/ are a range of preset settings
which can be quickly applied to a network interface. These are the zones
provided by firewalld sorted according to the default trust level of the
zones from untrusted to trusted:
drop
Any incoming network packets are dropped, there is no
reply. Only outgoing network connections are possible. block
Any incoming network connections are rejected with an
icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited
for IPv6. Only network connections initiated from within the system are
possible. public
For use in public areas. You do not trust the other
computers on the network to not harm your computer. Only selected incoming
connections are accepted. external
For use on external networks with masquerading enabled
especially for routers. You do not trust the other computers on the network to
not harm your computer. Only selected incoming connections are accepted. dmz
For computers in your demilitarized zone that are
publicly-accessible with limited access to your internal network. Only selected
incoming connections are accepted. work
For use in work areas. You mostly trust the other computers
on networks to not harm your computer. Only selected incoming connections are
accepted. home
For use in home areas. You mostly trust the other computers
on networks to not harm your computer. Only selected incoming connections are
accepted. internal
For use on internal networks. You mostly trust the
other computers on the networks to not harm your computer. Only selected
incoming connections are accepted. trusted
All network connections are accepted.
It is possible to designate one of these zones to be the default zone. When
interface connections are added to NetworkManager , they are assigned
to the default zone. On installation, the default zone in firewalld is set to
be the public zone.
To find out all the settings of a zone, for example the public zone,
enter the following command as root:
# firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
# firewall-cmd --zone=public --list-all
public
interfaces:
services: mdns dhcpv6-client ssh
ports:
forward-ports:
icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
# firewall-cmd --get-service
The following listing displays the result of this command
on common SUSE Linux Enterprise 15 system:
# firewall-cmd --get-service
amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
samba samba-client smtp ssh telnet tftp tftp-client transmission-client
vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld
service reload, enter the following command as root:
# firewall-cmd --get-service --permanent
|
Rule
Install firewalld Package
[ref] | The firewalld package can be installed with the following command:
$ sudo zypper install firewalld
| Rationale: | "Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols.
Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best.
Remote access is access to DoD nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless.
SUSE Linux Enterprise 15 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity.
Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets)." | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_package_firewalld_installed | Identifiers: | CCE-85698-9 | References: | disa | CCI-002314 | nist | CM-7, CM-7.1(iii), CM-7(b), AC-17(1) | ospp | FMT_SMF_EXT.1 | os-srg | SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232 | stigid | SLES-15-010220 | cis | 3.5.1.1 | pcidss4 | 1.2.1, 1.2 | stigref | SV-234821r958480_rule |
| |
|
Rule
Verify firewalld Enabled
[ref] |
The firewalld service can be enabled with the following command:
$ sudo systemctl enable firewalld.service
| Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_service_firewalld_enabled | Identifiers: | CCE-85751-6 | References: | cis-csc | 11, 3, 9 | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05 | cui | 3.1.3, 3.4.7 | disa | CCI-000366, CCI-000382, CCI-002314 | isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3 | isa-62443-2013 | SR 7.6 | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4 | nerc-cip | CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3 | nist | CM-7, CM-7.1(iii), CM-7(b), AC-17(1) | nist-csf | PR.IP-1 | ospp | FMT_SMF_EXT.1 | os-srg | SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232 | stigid | SLES-15-010220 | cis | 3.5.1.3 | pcidss4 | 1.2.1, 1.2 | stigref | SV-234821r958480_rule |
| |
|
Group
Strengthen the Default Ruleset
Group contains 2 rules |
[ref]
The default rules can be strengthened. The system
scripts that activate the firewall rules expect them to be defined
in configuration files under the /etc/firewalld/services
and /etc/firewalld/zones directories.
The following recommendations describe how to strengthen the
default ruleset configuration file. An alternative to editing this
configuration file is to create a shell script that makes calls to
the firewall-cmd program to load in rules under the /etc/firewalld/services
and /etc/firewalld/zones directories.
Instructions apply to both unless otherwise noted. Language and address
conventions for regular firewalld rules are used throughout this section. Warning:
The program firewall-config
allows additional services to penetrate the default firewall rules
and automatically adjusts the firewalld ruleset(s). |
Rule
Ensure firewall rules exist for all open ports
[ref] | Any ports that have been opened on non-loopback addresses need firewall rules to govern
traffic. Warning:
To prevent denying any access to the system, automatic remediation
of this control is not available. Remediation must be automated as
a component of machine provisioning, or followed manually as outlined
above. | Rationale: | Without a firewall rule configured for open ports default firewall policy will drop all
packets to these ports. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_ensure_firewall_rules_for_open_ports | Identifiers: | CCE-91411-9 | References: | | |
|
Rule
Set Default firewalld Zone for Incoming Packets
[ref] | To set the default zone to drop for
the built-in default zone which processes incoming IPv4 and IPv6 packets,
modify the following line in
/etc/firewalld/firewalld.conf to be:
DefaultZone=drop
Warning:
To prevent denying any access to the system, automatic remediation
of this control is not available. Remediation must be automated as
a component of machine provisioning, or followed manually as outlined
above. | Rationale: | In firewalld the default zone is applied only after all
the applicable rules in the table are examined for a match. Setting the
default zone to drop implements proper design for a firewall, i.e.
any packets which are not explicitly permitted should not be
accepted. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_firewalld_default_zone | Identifiers: | CCE-91410-1 | References: | cis-csc | 11, 14, 3, 9 | cjis | 5.10.1 | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | cui | 3.1.3, 3.4.7, 3.13.6 | disa | CCI-000366 | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | ism | 1416 | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | nist | CA-3(5), CM-7(b), SC-7(23), CM-6(a) | nist-csf | PR.IP-1, PR.PT-3 | ospp | FMT_MOF_EXT.1 | pcidss | Req-1.4 | os-srg | SRG-OS-000480-GPOS-00227 | cis | 3.5.1.4 | pcidss4 | 1.3.1, 1.3 |
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Group
iptables and ip6tables
Group contains 1 group and 3 rules |
[ref]
A host-based firewall called netfilter is included as
part of the Linux kernel distributed with the system. It is
activated by default. This firewall is controlled by the program
iptables , and the entire capability is frequently referred to by
this name. An analogous program called ip6tables handles filtering
for IPv6.
Unlike TCP Wrappers, which depends on the network server
program to support and respect the rules written, netfilter
filtering occurs at the kernel level, before a program can even
process the data from the network packet. As such, any program on
the system is affected by the rules written.
This section provides basic information about strengthening
the iptables and ip6tables configurations included with the system.
For more complete information that may allow the construction of a
sophisticated ruleset tailored to your environment, please consult
the references at the end of this section. |
Group
Inspect and Activate Default Rules
Group contains 3 rules |
[ref]
View the currently-enforced iptables rules by running
the command:
$ sudo iptables -nL --line-numbers
The command is analogous for ip6tables .
If the firewall does not appear to be active (i.e., no rules
appear), activate it and ensure that it starts at boot by issuing
the following commands (and analogously for ip6tables ):
$ sudo service iptables restart
The default iptables rules are:
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
3 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
4 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
5 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
The ip6tables default rules are essentially the same. |
Rule
Set Default ip6tables Policy for Incoming Packets
[ref] | To set the default policy to DROP (instead of ACCEPT) for
the built-in INPUT chain which processes incoming packets,
add or correct the following line in
/etc/sysconfig/ip6tables :
:INPUT DROP [0:0]
If changes were required, reload the ip6tables rules:
$ sudo service ip6tables reload
| Rationale: | In ip6tables , the default policy is applied only after all
the applicable rules in the table are examined for a match. Setting the
default policy to DROP implements proper design for a firewall, i.e.
any packets which are not explicitly permitted should not be
accepted. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_ip6tables_default_rule | Identifiers: | CCE-91342-6 | References: | cis-csc | 11, 14, 3, 9 | cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06 | isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3 | isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6 | iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2 | nerc-cip | CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3 | nist | AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a) | nist-csf | PR.IP-1, PR.PT-3 | cis | 3.5.3.3.1 | pcidss4 | 1.4.1, 1.4 |
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Rule
Set configuration for IPv6 loopback traffic
[ref] | Configure the loopback interface to accept traffic.
Configure all other interfaces to deny traffic to the loopback
network. Warning:
Changing firewall settings while connected over network can
result in being locked out of the system. | Rationale: | Loopback traffic is generated between processes on machine and is
typically critical to operation of the system. The loopback interface
is the only place that loopback network traffic should be seen,
all other interfaces should ignore traffic on this network as an
anti-spoofing measure. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_ipv6_loopback_traffic | Identifiers: | CCE-91346-7 | References: | | |
|
Rule
Set configuration for loopback traffic
[ref] | Configure the loopback interface to accept traffic.
Configure all other interfaces to deny traffic to the loopback
network. Warning:
Changing firewall settings while connected over network can
result in being locked out of the system. | Rationale: | Loopback traffic is generated between processes on machine and is
typically critical to operation of the system. The loopback interface
is the only place that loopback network traffic should be seen, all
other interfaces should ignore traffic on this network as an
anti-spoofing measure. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_set_loopback_traffic | Identifiers: | CCE-91345-9 | References: | | |
|
Group
IPv6
Group contains 1 group and 1 rule |
[ref]
The system includes support for Internet Protocol
version 6. A major and often-mentioned improvement over IPv4 is its
enormous increase in the number of available addresses. Another
important feature is its support for automatic configuration of
many network settings. |
Group
Configure IPv6 Settings if Necessary
Group contains 1 rule |
[ref]
A major feature of IPv6 is the extent to which systems
implementing it can automatically configure their networking
devices using information from the network. From a security
perspective, manually configuring important configuration
information is preferable to accepting it from the network
in an unauthenticated fashion. |
Rule
Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default
[ref] | 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=0
To 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
| Rationale: | 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. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route | Identifiers: | CCE-85653-4 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9 | cobit5 | APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02 | cui | 3.1.20 | disa | CCI-000366 | isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3 | isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nist | CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv) | nist-csf | DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4 | pcidss | Req-1.4.3 | os-srg | SRG-OS-000480-GPOS-00227 | stigid | SLES-15-040321 | cis | 3.3.1 | anssi | R13 | pcidss4 | 1.4.2, 1.4 | stigref | SV-235017r991589_rule |
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Group
Kernel Parameters Which Affect Networking
Group contains 2 groups and 9 rules |
[ref]
The sysctl utility is used to set
parameters which affect the operation of the Linux kernel. Kernel parameters
which affect networking and have security implications are described here. |
Group
Network Related Kernel Runtime Parameters for Hosts and Routers
Group contains 6 rules |
[ref]
Certain kernel parameters should be set for systems which are
acting as either hosts or routers to improve the system's ability defend
against certain types of IPv4 protocol attacks. |
Rule
Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
[ref] | To set the runtime status of the net.ipv4.conf.all.rp_filter kernel parameter, run the following command: $ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d : net.ipv4.conf.all.rp_filter = 1
| Rationale: | Enabling reverse path filtering drops packets with source addresses
that should not have been able to be received on the interface they were
received on. It should not be used on systems which are routers for
complicated networks, but is helpful for end hosts and routers serving small
networks. | Severity: | medium | Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter | Identifiers: | CCE-91218-8 | References: | cis-csc | 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9 | cobit5 | APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02 | cui | 3.1.20 | disa | CCI-000366, CCI-001551 | isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3 | isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6 | iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5 | nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a) | nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4 | pcidss | Req-1.4.3 | os-srg | SRG-OS-000480-GPOS-00227 | cis | 3.3.7 | anssi | R12 | pcidss4 | 1.4.3, 1.4 |
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