Guide to the Secure Configuration of Debian 12

with profile Profile for ANSSI DAT-NT28 High (Enforced) Level
This profile contains items for GNU/Linux installations storing sensitive information that can be accessible from unauthenticated or uncontroled networks.

The SCAP Security Guide Project
https://www.open-scap.org/security-policies/scap-security-guide

This guide presents a catalog of security-relevant configuration settings for Debian 12. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the scap-security-guide package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.

Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.

Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

Profile Information

Profile Title	Profile for ANSSI DAT-NT28 High (Enforced) Level
Profile ID	xccdf_org.ssgproject.content_profile_anssi_np_nt28_high

CPE Platforms

cpe:/o:debian:debian_linux:12

Revision History

Current version: 0.1.76

draft (as of 2024-12-21)

System Settings
Services
System Accounting with auditd

Checklist

Group Guide to the Secure Configuration of Debian 12 Group contains 23 groups and 50 rules

Group System Settings Group contains 14 groups and 33 rules

[ref] Contains rules that check correct system settings.

Group Installing and Maintaining Software Group contains 2 groups and 7 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 Disk Partitioning Group contains 5 rules

[ref] To ensure separation and protection of data, there are top-level system directories which should be placed on their own physical partition or logical volume. The installer's default partitioning scheme creates separate logical volumes for /, /boot, and swap.

If starting with any of the default layouts, check the box to \"Review and modify partitioning.\" This allows for the easy creation of additional logical volumes inside the volume group already created, though it may require making /'s logical volume smaller to create space. In general, using logical volumes is preferable to using partitions because they can be more easily adjusted later.
If creating a custom layout, create the partitions mentioned in the previous paragraph (which the installer will require anyway), as well as separate ones described in the following sections.

If a system has already been installed, and the default partitioning scheme was used, it is possible but nontrivial to modify it to create separate logical volumes for the directories listed above. The Logical Volume Manager (LVM) makes this possible.

Rule Ensure /home Located On Separate Partition [ref]

If user home directories will be stored locally, create a separate partition for /home at installation time (or migrate it later using LVM). If /home will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.

Rationale:

Ensuring that /home is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_partition_for_home

References:

cis-csc	12, 15, 8
cobit5	APO13.01, DSS05.02
disa	CCI-000366
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.13.1.1, A.13.2.1, A.14.1.3
nist	CM-6(a), SC-5(2)
nist-csf	PR.PT-4
os-srg	SRG-OS-000480-GPOS-00227
anssi	R28

Rule Ensure /tmp Located On Separate Partition [ref]

The /tmp directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.

Rationale:

The /tmp partition is used as temporary storage by many programs. Placing /tmp in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_partition_for_tmp

References:

cis-csc	12, 15, 8
cobit5	APO13.01, DSS05.02
disa	CCI-000366
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.13.1.1, A.13.2.1, A.14.1.3
nist	CM-6(a), SC-5(2)
nist-csf	PR.PT-4
os-srg	SRG-OS-000480-GPOS-00227

Rule Ensure /var Located On Separate Partition [ref]

The /var directory is used by daemons and other system services to store frequently-changing data. Ensure that /var has its own partition or logical volume at installation time, or migrate it using LVM.

Rationale:

Ensuring that /var is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the /var directory to contain world-writable directories installed by other software packages.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_partition_for_var

References:

cis-csc	12, 15, 8
cobit5	APO13.01, DSS05.02
disa	CCI-000366
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.13.1.1, A.13.2.1, A.14.1.3
nist	CM-6(a), SC-5(2)
nist-csf	PR.PT-4
os-srg	SRG-OS-000480-GPOS-00227
anssi	R28

Rule Ensure /var/log Located On Separate Partition [ref]

System logs are stored in the /var/log directory. Ensure that /var/log has its own partition or logical volume at installation time, or migrate it using LVM.

Rationale:

Placing /var/log in its own partition enables better separation between log files and other files in /var/.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_partition_for_var_log

References:

cis-csc	1, 12, 14, 15, 16, 3, 5, 6, 8
cobit5	APO11.04, APO13.01, BAI03.05, DSS05.02, 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, 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.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3
nerc-cip	CIP-007-3 R6.5
nist	CM-6(a), AU-4, SC-5(2)
nist-csf	PR.PT-1, PR.PT-4
os-srg	SRG-OS-000480-GPOS-00227
anssi	R28

Rule Ensure /var/log/audit Located On Separate Partition [ref]

Audit logs are stored in the /var/log/audit directory. Ensure that /var/log/audit has its own partition or logical volume at installation time, or migrate it using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.

Rationale:

Placing /var/log/audit in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_partition_for_var_log_audit

References:

cis-csc	1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 8
cobit5	APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.02, DSS05.04, DSS05.07, MEA02.01
disa	CCI-000366, CCI-001849
hipaa	164.312(a)(2)(ii)
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, 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 7.2, SR 7.6
iso27001-2013	A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.17.2.1
nerc-cip	CIP-007-3 R6.5
nist	CM-6(a), AU-4, SC-5(2)
nist-csf	PR.DS-4, PR.PT-1, PR.PT-4
ospp	FMT_SMF_EXT.1
os-srg	SRG-OS-000341-GPOS-00132, SRG-OS-000480-GPOS-00227
app-srg-ctr	SRG-APP-000357-CTR-000800
anssi	R71

Group Sudo Group contains 2 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 Ensure Users Re-Authenticate for Privilege Escalation - sudo !authenticate [ref]

The sudo !authenticate option, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that the !authenticate option does not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.

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_remove_no_authenticate

References:

cis-csc	1, 12, 15, 16, 5
cobit5	DSS05.04, DSS05.10, DSS06.03, DSS06.10
disa	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, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict


for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+\!authenticate.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "!authenticate" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Find /etc/sudoers.d/ files
  ansible.builtin.find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_no_authenticate

- name: Remove lines containing !authenticate from sudoers files
  ansible.builtin.replace:
    regexp: (^(?!#).*[\s]+\!authenticate.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_no_authenticate

Rule Ensure Users Re-Authenticate for Privilege Escalation - sudo NOPASSWD [ref]

The sudo NOPASSWD tag, when specified, allows a user to execute commands using sudo without having to authenticate. This should be disabled by making sure that the NOPASSWD tag does not exist in /etc/sudoers configuration file or any sudo configuration snippets in /etc/sudoers.d/.

Rationale:

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sudo_remove_nopasswd

References:

cis-csc	1, 12, 15, 16, 5
cobit5	DSS05.04, DSS05.10, DSS06.03, DSS06.10
disa	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, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict


for f in /etc/sudoers /etc/sudoers.d/* ; do
  if [ ! -e "$f" ] ; then
    continue
  fi
  matching_list=$(grep -P '^(?!#).*[\s]+NOPASSWD[\s]*\:.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      # comment out "NOPASSWD" matches to preserve user data
      sed -i "s/^${entry}$/# &/g" $f
    done <<< "$matching_list"

    /usr/sbin/visudo -cf $f &> /dev/null || echo "Fail to validate $f with visudo"
  fi
done

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Find /etc/sudoers.d/ files
  ansible.builtin.find:
    paths:
    - /etc/sudoers.d/
  register: sudoers
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_nopasswd

- name: Remove lines containing NOPASSWD from sudoers files
  ansible.builtin.replace:
    regexp: (^(?!#).*[\s]+NOPASSWD[\s]*\:.*$)
    replace: '# \g<1>'
    path: '{{ item.path }}'
    validate: /usr/sbin/visudo -cf %s
  with_items:
  - path: /etc/sudoers
  - '{{ sudoers.files }}'
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-11
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sudo_remove_nopasswd

Group GRUB2 bootloader configuration Group contains 1 rule

[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 Debian 12 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.

Rule IOMMU configuration directive [ref]

On x86 architecture supporting VT-d, the IOMMU manages the access control policy between the hardware devices and some of the system critical units such as the memory. Configure the default Grub2 kernel command line to contain iommu=force as follows:

# grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) iommu=force"

Warning: Depending on the hardware, devices and operating system used, enabling IOMMU can cause hardware instabilities. Proper function and stability should be assessed before applying remediation to production systems.

Rationale:

On x86 architectures, activating the I/OMMU prevents the system from arbitrary accesses potentially made by hardware devices.

Severity:

unknown

Rule ID: xccdf_org.ssgproject.content_rule_grub2_enable_iommu_force

References:

anssi	R7

Remediation Shell script ⇲

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}\n' 'grub2-common' 2>/dev/null | grep -q installed && { [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; }; then

# Correct the form of default kernel command line in GRUB
if grep -q '^\s*GRUB_CMDLINE_LINUX=.*iommu=.*"'  '/etc/default/grub' ; then
       # modify the GRUB command-line if an iommu= arg already exists
       sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)iommu=[^[:space:]]\+\(.*\"\)/\1iommu=force\2/"  '/etc/default/grub'
# Add to already existing GRUB_CMDLINE_LINUX parameters
elif grep -q '^\s*GRUB_CMDLINE_LINUX='  '/etc/default/grub' ; then
       # no iommu=arg is present, append it
       sed -i "s/\(^\s*GRUB_CMDLINE_LINUX=\".*\)\"/\1 iommu=force\"/"  '/etc/default/grub'
# Add GRUB_CMDLINE_LINUX parameters line
else
       echo "GRUB_CMDLINE_LINUX=\"iommu=force\"" >> '/etc/default/grub'
fi
update-grub

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	medium
Disruption:	low
Reboot:	true
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Check iommu argument exists
  command: grep '^\s*GRUB_CMDLINE_LINUX=.*iommu=' /etc/default/grub
  failed_when: false
  register: argcheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Check iommu argument exists
  command: grep '^\s*GRUB_CMDLINE_LINUX=' /etc/default/grub
  failed_when: false
  register: linecheck
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Add iommu argument
  ansible.builtin.lineinfile:
    line: GRUB_CMDLINE_LINUX="iommu=force "
    state: present
    dest: /etc/default/grub
    create: true
    mode: '0644'
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
    linecheck.rc != 0
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Replace existing iommu argument
  replace:
    path: /etc/default/grub
    regexp: iommu=[a-zA-Z0-9,]+
    replace: iommu=force
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck is not skipped and linecheck is not skipped and argcheck.rc == 0 and
    linecheck.rc == 0
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Add iommu argument
  replace:
    path: /etc/default/grub
    regexp: (^\s*GRUB_CMDLINE_LINUX=.*)"
    replace: \1 iommu=force"
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - argcheck is not skipped and linecheck is not skipped and argcheck.rc != 0 and
    linecheck.rc == 0
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

- name: Update grub defaults and the bootloader menu
  command: /usr/sbin/update-grub
  when:
  - '"grub2-common" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - grub2_enable_iommu_force
  - low_disruption
  - medium_complexity
  - reboot_required
  - restrict_strategy
  - unknown_severity

Group Configure Syslog Group contains 3 groups and 8 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 Debian 12, 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 Debian 12 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 adm. 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 adm, run the following command to correct this:

$ sudo chgrp adm 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

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
anssi	R71
pcidss4	10.3.2, 10.3

Remediation Shell script ⇲

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed && dpkg-query --show --showformat='${db:Status-Status}\n' 'rsyslog' 2>/dev/null | grep -q installed; then

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chgrp"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "adm" "$LOG_FILE_PATH"
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	false
Strategy:	configure

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Get IncludeConfig directive
  ansible.builtin.shell: |
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Get include files directives
  ansible.builtin.shell: |
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files old format
  ansible.builtin.shell: |
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Extract log files new format
  ansible.builtin.shell: |
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

- name: Ensure Log Files Are Owned By Appropriate Group -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    group: adm
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_groupownership

Rule Ensure Log Files Are Owned By Appropriate User [ref]

The owner of all log files written by rsyslog should be adm. 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 adm, run the following command to correct this:

$ sudo chown adm LOGFILE

Rationale:

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_rsyslog_files_ownership

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
anssi	R71
pcidss4	10.3.2, 10.3

Remediation Shell script ⇲

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed && dpkg-query --show --showformat='${db:Status-Status}\n' 'rsyslog' 2>/dev/null | grep -q installed; then

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chown"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "root" "$LOG_FILE_PATH"
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	false
Strategy:	configure

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Get IncludeConfig directive
  ansible.builtin.shell: |
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Get include files directives
  ansible.builtin.shell: |
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Extract log files old format
  ansible.builtin.shell: |
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Extract log files new format
  ansible.builtin.shell: |
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

- name: Ensure Log Files Are Owned By Appropriate User -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    owner: root
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.2
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_ownership

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

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
anssi	R71
pcidss4	10.3.1, 10.3

Remediation Shell script ⇲

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed && dpkg-query --show --showformat='${db:Status-Status}\n' 'rsyslog' 2>/dev/null | grep -q installed; then

# List of log file paths to be inspected for correct permissions
# * Primarily inspect log file paths listed in /etc/rsyslog.conf
RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
# * And also the log file paths listed after rsyslog's $IncludeConfig directive
#   (store the result into array for the case there's shell glob used as value of IncludeConfig)
readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

# Declare an array to hold the final list of different log file paths
declare -a LOG_FILE_PATHS

# Array to hold all rsyslog config entries
RSYSLOG_CONFIGS=()
RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

# Get full list of files to be checked
# RSYSLOG_CONFIGS may contain globs such as
# /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
# So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
RSYSLOG_CONFIG_FILES=()
for ENTRY in "${RSYSLOG_CONFIGS[@]}"
do
	# If directory, rsyslog will search for config files in recursively.
	# However, files in hidden sub-directories or hidden files will be ignored.
	if [ -d "${ENTRY}" ]
	then
		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
	elif [ -f "${ENTRY}" ]
	then
		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
	else
		echo "Invalid include object: ${ENTRY}"
	fi
done

# Browse each file selected above as containing paths of log files
# ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	# From each of these files extract just particular log file path(s), thus:
	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
	# * Ignore empty lines,
	# * Strip quotes and closing brackets from paths.
	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
	# * From the remaining valid rows select only fields constituting a log file path
	# Text file column is understood to represent a log file path if and only if all of the
	# following are met:
	# * it contains at least one slash '/' character,
	# * it is preceded by space
	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
	# Search log file for path(s) only in case it exists!
	if [[ -f "${LOG_FILE}" ]]
	then
		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
		# Since above sed command might return more than one item (delimited by newline), split
		# the particular matches entries into new array specific for this log file
		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
		# items from newly created array for this log file
		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
		# Delete the temporary array
		unset ARRAY_FOR_LOG_FILE
	fi
done

# Check for RainerScript action log format which might be also multiline so grep regex is a bit
# curly:
# extract possibly multiline action omfile expressions
# extract File="logfile" expression
# match only "logfile" expression
for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
do
	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"")")
done

# Ensure the correct attribute if file exists
FILE_CMD="chmod"
for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
do
	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
	if [ -z "$LOG_FILE_PATH" ]
	then
		continue
	fi
	$FILE_CMD "0640" "$LOG_FILE_PATH"
done

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	false
Strategy:	configure

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Set rsyslog logfile configuration
    facts
  ansible.builtin.set_fact:
    rsyslog_etc_config: /etc/rsyslog.conf
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Get IncludeConfig directive
  ansible.builtin.shell: |
    grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
  register: rsyslog_old_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Get include files directives
  ansible.builtin.shell: |
    awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
  register: rsyslog_new_inc
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Aggregate rsyslog includes
  ansible.builtin.set_fact:
    include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
      }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - List all config files
  ansible.builtin.find:
    paths: '{{ item | dirname }}'
    patterns: '{{ item | basename }}'
    hidden: false
    follow: true
  loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - include_config_output is defined
  register: rsyslog_config_files
  failed_when: false
  changed_when: false
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Extract log files old format
  ansible.builtin.shell: |
    grep -oP '^[^(\s|#|\$)]+[\s]+.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
    awk '{print $NF}' | \
    sed -e 's/^-//' || true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_old
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Extract log files new format
  ansible.builtin.shell: |
    grep -ozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
    grep -aoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
    grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
    tr -d "\""|| true
  loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
  register: log_files_new
  changed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  - rsyslog_config_files is not skipped
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions - Sum all log files found
  ansible.builtin.set_fact:
    log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
      | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
      | list | flatten | unique }}'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

- name: Ensure System Log Files Have Correct Permissions -Setup log files attribute
  ansible.builtin.file:
    path: '{{ item }}'
    mode: '0640'
    state: file
  loop: '{{ log_files | list | flatten | unique }}'
  failed_when: false
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"rsyslog" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.5.1
  - PCI-DSS-Req-10.5.2
  - PCI-DSSv4-10.3
  - PCI-DSSv4-10.3.1
  - configure_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - no_reboot_needed
  - rsyslog_files_permissions

Group Ensure All Logs are Rotated by logrotate Group contains 1 rule

[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 Runs Periodically [ref]

The logrotate utility allows for the automatic rotation of log files. The frequency of rotation is specified in /etc/logrotate.conf, which triggers a cron task or a timer. To configure logrotate to run daily, add or correct the following line in /etc/logrotate.conf:

# rotate log files frequency
daily

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_ensure_logrotate_activated

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
anssi	R71

Remediation Shell script ⇲

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed && { dpkg-query --show --showformat='${db:Status-Status}\n' 'logrotate' 2>/dev/null | grep -q installed; }; then

LOGROTATE_CONF_FILE="/etc/logrotate.conf"

DEBIAN_FRONTEND=noninteractive apt-get install -y "crontabs"
CRON_DAILY_LOGROTATE_FILE="/etc/cron.daily/logrotate"


# daily rotation is configured
grep -q "^daily$" $LOGROTATE_CONF_FILE|| echo "daily" >> $LOGROTATE_CONF_FILE

# remove any line configuring weekly, monthly or yearly rotation
sed -i '/^\s*\(weekly\|monthly\|yearly\).*$/d' $LOGROTATE_CONF_FILE


# configure cron.daily if not already
if ! grep -q "^[[:space:]]*/usr/sbin/logrotate[[:alnum:][:blank:][:punct:]]*$LOGROTATE_CONF_FILE$" $CRON_DAILY_LOGROTATE_FILE; then
	echo '#!/bin/sh' > $CRON_DAILY_LOGROTATE_FILE
	echo "/usr/sbin/logrotate $LOGROTATE_CONF_FILE" >> $CRON_DAILY_LOGROTATE_FILE
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - configure_strategy
  - ensure_logrotate_activated
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure daily log rotation in /etc/logrotate.conf
  lineinfile:
    create: true
    dest: /etc/logrotate.conf
    regexp: ^daily$
    line: daily
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"logrotate" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - configure_strategy
  - ensure_logrotate_activated
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Make sure daily log rotation setting is not overriden in /etc/logrotate.conf
  lineinfile:
    create: false
    dest: /etc/logrotate.conf
    regexp: ^[\s]*(weekly|monthly|yearly)$
    state: absent
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"logrotate" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - configure_strategy
  - ensure_logrotate_activated
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Configure cron.daily if not already
  block:

  - name: Add shebang
    lineinfile:
      path: /etc/cron.daily/logrotate
      line: '#!/bin/sh'
      insertbefore: BOF
      create: true

  - name: Add logrotate call
    lineinfile:
      path: /etc/cron.daily/logrotate
      line: /usr/sbin/logrotate /etc/logrotate.conf
      regexp: ^[\s]*/usr/sbin/logrotate[\s\S]*/etc/logrotate.conf$
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"logrotate" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.7
  - configure_strategy
  - ensure_logrotate_activated
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Group Configure rsyslogd to Accept Remote Messages If Acting as a Log Server Group contains 2 rules

[ref] By default, rsyslog does not listen over the network for log messages. If needed, modules can be enabled to allow the rsyslog daemon to receive messages from other systems and for the system thus to act as a log server. If the system is not a log server, then lines concerning these modules should remain commented out.

Rule Ensure syslog-ng is Installed [ref]

syslog-ng can be installed in replacement of rsyslog. The syslog-ng-core package can be installed with the following command:

$ apt-get install syslog-ng-core

Rationale:

The syslog-ng-core package provides the syslog-ng daemon, which provides system logging services.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_package_syslogng_installed

References:

cis-csc	1, 14, 15, 16, 3, 5, 6
cobit5	APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
disa	CCI-001311, CCI-001312
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

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

DEBIAN_FRONTEND=noninteractive apt-get install -y "syslog-ng"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation OSBuild Blueprint snippet ⇲


[[packages]]
name = "syslog-ng"
version = "*"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_syslogng_installed

- name: Ensure syslog-ng is installed
  package:
    name: syslog-ng
    state: present
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_syslogng_installed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include install_syslog-ng

class install_syslog-ng {
  package { 'syslog-ng':
    ensure => 'installed',
  }
}

Rule Enable syslog-ng Service [ref]

The syslog-ng service (in replacement of rsyslog) provides syslog-style logging by default on Debian. The syslog-ng service can be enabled with the following command:

$ sudo systemctl enable syslog-ng.service

Rationale:

The syslog-ng service must be running in order to provide logging services, which are essential to system administration.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_service_syslogng_enabled

References:

cis-csc	1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9
cobit5	APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
disa	CCI-001311, CCI-001312, CCI-001557, CCI-001851
isa-62443-2009	4.3.2.6.7, 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, SR 6.1, SR 6.2, SR 7.1, SR 7.2
iso27001-2013	A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, A.17.2.1
nist	CM-6(a), AU-4(1)
nist-csf	DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.DS-4, PR.PT-1

Remediation OSBuild Blueprint snippet ⇲


[customizations.services]
enabled = ["syslog-ng"]

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-4(1)
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_syslogng_enabled

- name: Enable syslog-ng Service - Enable service syslog-ng
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable syslog-ng Service - Enable Service syslog-ng
    ansible.builtin.systemd:
      name: syslog-ng
      enabled: true
      state: started
      masked: false
    when:
    - '"syslog-ng" in ansible_facts.packages'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AU-4(1)
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_syslogng_enabled

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include enable_syslog-ng

class enable_syslog-ng {
  service {'syslog-ng':
    enable => true,
    ensure => 'running',
  }
}

Rule Ensure rsyslog is Installed [ref]

Rsyslog is installed by default. The rsyslog package can be installed with the following command:

 $ apt-get install rsyslog

Rationale:

The rsyslog package provides the rsyslog daemon, which provides system logging services.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_package_rsyslog_installed

References:

cis-csc	1, 14, 15, 16, 3, 5, 6
cobit5	APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
disa	CCI-000366, CCI-000154, CCI-001851
hipaa	164.312(a)(2)(ii)
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
os-srg	SRG-OS-000479-GPOS-00224, SRG-OS-000051-GPOS-00024, SRG-OS-000480-GPOS-00227

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

DEBIAN_FRONTEND=noninteractive apt-get install -y "rsyslog"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation OSBuild Blueprint snippet ⇲


[[packages]]
name = "rsyslog"
version = "*"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_rsyslog_installed

- name: Ensure rsyslog is installed
  package:
    name: rsyslog
    state: present
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_rsyslog_installed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include install_rsyslog

class install_rsyslog {
  package { 'rsyslog':
    ensure => 'installed',
  }
}

Rule Enable rsyslog Service [ref]

The rsyslog service provides syslog-style logging by default on Debian 12. The rsyslog service can be enabled with the following command:

$ sudo systemctl enable rsyslog.service

Rationale:

The rsyslog service must be running in order to provide logging services, which are essential to system administration.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_service_rsyslog_enabled

References:

cis-csc	1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9
cobit5	APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO13.01, BAI03.05, BAI04.04, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
disa	CCI-000366
hipaa	164.312(a)(2)(ii)
isa-62443-2009	4.3.2.6.7, 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, SR 6.1, SR 6.2, SR 7.1, SR 7.2
iso27001-2013	A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2, A.17.2.1
nist	CM-6(a), AU-4(1)
nist-csf	DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.DS-4, PR.PT-1
os-srg	SRG-OS-000480-GPOS-00227

Remediation OSBuild Blueprint snippet ⇲


[customizations.services]
enabled = ["rsyslog"]

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-4(1)
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_rsyslog_enabled

- name: Enable rsyslog Service - Enable service rsyslog
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable rsyslog Service - Enable Service rsyslog
    ansible.builtin.systemd:
      name: rsyslog
      enabled: true
      state: started
      masked: false
    when:
    - '"rsyslog" in ansible_facts.packages'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AU-4(1)
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_rsyslog_enabled

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include enable_rsyslog

class enable_rsyslog {
  service {'rsyslog':
    enable => true,
    ensure => 'running',
  }
}

Group File Permissions and Masks Group contains 5 groups and 17 rules

[ref] Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access.

Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn.

The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Debian 12 installations:

$ mount -t xfs | awk '{print $3}'

For any systems that use a different local filesystem type, modify this command as appropriate.

Group Verify Permissions on Important Files and Directories Group contains 1 group and 15 rules

[ref] Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.

Group Verify Permissions on Files with Local Account Information and Credentials Group contains 12 rules

[ref] The default restrictive permissions for files which act as important security databases such as passwd, shadow, group, and gshadow files must be maintained. Many utilities need read access to the passwd file in order to function properly, but read access to the shadow file allows malicious attacks against system passwords, and should never be enabled.

Rule Verify Group Who Owns group File [ref]

To properly set the group owner of /etc/group, run the command:

$ sudo chgrp root /etc/group

Rationale:

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_groupowner_etc_group

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chgrp 0 /etc/group

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/group
  file:
    path: /etc/group
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Group Who Owns gshadow File [ref]

To properly set the group owner of /etc/gshadow, run the command:

$ sudo chgrp shadow /etc/gshadow

Rationale:

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow

References:

cis-csc	12, 13, 14, 15, 16, 18, 3, 5
cobit5	APO01.06, DSS05.04, DSS05.07, DSS06.02
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chgrp 42 /etc/gshadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 42 on /etc/gshadow
  file:
    path: /etc/gshadow
    group: '42'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_groupowner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Group Who Owns passwd File [ref]

To properly set the group owner of /etc/passwd, run the command:

$ sudo chgrp root /etc/passwd

Rationale:

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chgrp 0 /etc/passwd

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    group: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Group Who Owns shadow File [ref]

To properly set the group owner of /etc/shadow, run the command:

$ sudo chgrp shadow /etc/shadow

Rationale:

The /etc/shadow file stores password hashes. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chgrp 42 /etc/shadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure group owner 42 on /etc/shadow
  file:
    path: /etc/shadow
    group: '42'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify User Who Owns group File [ref]

To properly set the owner of /etc/group, run the command:

$ sudo chown root /etc/group

Rationale:

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_owner_etc_group

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chown 0 /etc/group

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/group
  file:
    path: /etc/group
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify User Who Owns gshadow File [ref]

To properly set the owner of /etc/gshadow, run the command:

$ sudo chown root /etc/gshadow

Rationale:

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_owner_etc_gshadow

References:

cis-csc	12, 13, 14, 15, 16, 18, 3, 5
cobit5	APO01.06, DSS05.04, DSS05.07, DSS06.02
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chown 0 /etc/gshadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/gshadow
  file:
    path: /etc/gshadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_owner_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify User Who Owns passwd File [ref]

To properly set the owner of /etc/passwd, run the command:

$ sudo chown root /etc/passwd

Rationale:

The /etc/passwd file contains information about the users that are configured on the system. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_owner_etc_passwd

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chown 0 /etc/passwd

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/passwd
  file:
    path: /etc/passwd
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify User Who Owns shadow File [ref]

To properly set the owner of /etc/shadow, run the command:

$ sudo chown root /etc/shadow

Rationale:

The /etc/shadow file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_owner_etc_shadow

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

chown 0 /etc/shadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner 0 on /etc/shadow
  file:
    path: /etc/shadow
    owner: '0'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Permissions on group File [ref]

To properly set the permissions of /etc/group, run the command:

$ sudo chmod 0644 /etc/group

Rationale:

The /etc/group file contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_permissions_etc_group

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure





chmod u-xs,g-xws,o-xwt /etc/group

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/group
  stat:
    path: /etc/group
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
  file:
    path: /etc/group
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Permissions on gshadow File [ref]

To properly set the permissions of /etc/gshadow, run the command:

$ sudo chmod 0640 /etc/gshadow

Rationale:

The /etc/gshadow file contains group password hashes. Protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow

References:

cis-csc	12, 13, 14, 15, 16, 18, 3, 5
cobit5	APO01.06, DSS05.04, DSS05.07, DSS06.02
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure





chmod u-xs,g-xws,o-xwrt /etc/gshadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/gshadow
  stat:
    path: /etc/gshadow
  register: file_exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/gshadow
  file:
    path: /etc/gshadow
    mode: u-xs,g-xws,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - configure_strategy
  - file_permissions_etc_gshadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Permissions on passwd File [ref]

To properly set the permissions of /etc/passwd, run the command:

$ sudo chmod 0644 /etc/passwd

Rationale:

If the /etc/passwd file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure





chmod u-xs,g-xws,o-xwt /etc/passwd

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/passwd
  stat:
    path: /etc/passwd
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
  file:
    path: /etc/passwd
    mode: u-xs,g-xws,o-xwt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_passwd
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Permissions on shadow File [ref]

To properly set the permissions of /etc/shadow, run the command:

$ sudo chmod 0640 /etc/shadow

Rationale:

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow

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
disa	CCI-000366
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	CM-6(a), AC-6(1)
nist-csf	PR.AC-4, PR.DS-5
pcidss	Req-8.7.c
os-srg	SRG-OS-000480-GPOS-00227
anssi	R50
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure





chmod u-xs,g-xws,o-xwrt /etc/shadow

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Test for existence /etc/shadow
  stat:
    path: /etc/shadow
  register: file_exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure permission u-xs,g-xws,o-xwrt on /etc/shadow
  file:
    path: /etc/shadow
    mode: u-xs,g-xws,o-xwrt
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - CJIS-5.5.2.2
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_permissions_etc_shadow
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

Rule Verify Permissions on System.map Files [ref]

The System.map files are symbol map files generated during the compilation of the Linux kernel. They contain the mapping between kernel symbols and their corresponding memory addresses. In general, there is no need for non-root users to read these files. To properly set the permissions of /boot/System.map*, run the command:

$ sudo chmod 0600 /boot/System.map*

Rationale:

The purpose of System.map files is primarily for debugging and profiling the kernel. Unrestricted access to these files might disclose information useful to attackers and malicious software leading to more sophisticated exploitation.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_file_permissions_systemmap

References:

anssi	R29

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure





find -L /boot/ -maxdepth 1 -perm /u+xs,g+xwrs,o+xwrt  -type f -regextype posix-extended -regex '^.*System\.map.*$' -exec chmod u-xs,g-xwrs,o-xwrt {} \;

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	configure

- name: Find /boot/ file(s)
  command: find -H /boot/ -maxdepth 1 -perm /u+xs,g+xwrs,o+xwrt  -type f -regextype
    posix-extended -regex "^.*System\.map.*$"
  register: files_found
  changed_when: false
  failed_when: false
  check_mode: false
  tags:
  - configure_strategy
  - file_permissions_systemmap
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed

- name: Set permissions for /boot/ file(s)
  file:
    path: '{{ item }}'
    mode: u-xs,g-xwrs,o-xwrt
    state: file
  with_items:
  - '{{ files_found.stdout_lines }}'
  tags:
  - configure_strategy
  - file_permissions_systemmap
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed

Rule Enable Kernel Parameter to Enforce DAC on Hardlinks [ref]

To set the runtime status of the fs.protected_hardlinks kernel parameter, run the following command:

$ sudo sysctl -w fs.protected_hardlinks=1

To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:

fs.protected_hardlinks = 1

Rationale:

By enabling this kernel parameter, users can no longer create soft or hard links to files which they do not own. Disallowing such hardlinks mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sysctl_fs_protected_hardlinks

References:

disa	CCI-002235, CCI-002165
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)
os-srg	SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125
anssi	R14

Remediation Shell script ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

# Comment out any occurrences of fs.protected_hardlinks from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do


  # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
  if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

  matching_list=$(grep -P '^(?!#).*[\s]*fs.protected_hardlinks.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "fs.protected_hardlinks" matches to preserve user data
      sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for fs.protected_hardlinks
#
if [[ "$OSCAP_BOOTC_BUILD" != "YES" ]] ; then
    /sbin/sysctl -q -n -w fs.protected_hardlinks="1"
fi

#
# If fs.protected_hardlinks present in /etc/sysctl.conf, change value to "1"
#	else, add "fs.protected_hardlinks = 1" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.protected_hardlinks")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.protected_hardlinks\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^fs.protected_hardlinks\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_hardlinks

- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*fs.protected_hardlinks.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_hardlinks

- name: Comment out any occurrences of fs.protected_hardlinks from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*fs.protected_hardlinks
    replace: '#fs.protected_hardlinks'
  loop: '{{ find_sysctl_d.files }}'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_hardlinks

- name: Ensure sysctl fs.protected_hardlinks is set to 1
  sysctl:
    name: fs.protected_hardlinks
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_hardlinks

Rule Enable Kernel Parameter to Enforce DAC on Symlinks [ref]

To set the runtime status of the fs.protected_symlinks kernel parameter, run the following command:

$ sudo sysctl -w fs.protected_symlinks=1

To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:

fs.protected_symlinks = 1

Rationale:

By enabling this kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the UID of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sysctl_fs_protected_symlinks

References:

disa	CCI-002235, CCI-002165
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)
os-srg	SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125
anssi	R14

Remediation Shell script ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

# Comment out any occurrences of fs.protected_symlinks from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do


  # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
  if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

  matching_list=$(grep -P '^(?!#).*[\s]*fs.protected_symlinks.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "fs.protected_symlinks" matches to preserve user data
      sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for fs.protected_symlinks
#
if [[ "$OSCAP_BOOTC_BUILD" != "YES" ]] ; then
    /sbin/sysctl -q -n -w fs.protected_symlinks="1"
fi

#
# If fs.protected_symlinks present in /etc/sysctl.conf, change value to "1"
#	else, add "fs.protected_symlinks = 1" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.protected_symlinks")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "1"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.protected_symlinks\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^fs.protected_symlinks\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_symlinks

- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*fs.protected_symlinks.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_symlinks

- name: Comment out any occurrences of fs.protected_symlinks from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*fs.protected_symlinks
    replace: '#fs.protected_symlinks'
  loop: '{{ find_sysctl_d.files }}'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_symlinks

- name: Ensure sysctl fs.protected_symlinks is set to 1
  sysctl:
    name: fs.protected_symlinks
    value: '1'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_protected_symlinks

Group Restrict Programs from Dangerous Execution Patterns Group contains 2 groups and 2 rules

[ref] The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.

Group Disable Core Dumps Group contains 1 rule

[ref] A core dump file is the memory image of an executable program when it was terminated by the operating system due to errant behavior. In most cases, only software developers legitimately need to access these files. The core dump files may also contain sensitive information, or unnecessarily occupy large amounts of disk space.

Once a hard limit is set in /etc/security/limits.conf, or to a file within the /etc/security/limits.d/ directory, a user cannot increase that limit within his or her own session. If access to core dumps is required, consider restricting them to only certain users or groups. See the limits.conf man page for more information.

The core dumps of setuid programs are further protected. The sysctl variable fs.suid_dumpable controls whether the kernel allows core dumps from these programs at all. The default value of 0 is recommended.

Rule Disable Core Dumps for SUID programs [ref]

To set the runtime status of the fs.suid_dumpable kernel parameter, run the following command:

$ sudo sysctl -w fs.suid_dumpable=0

To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:

fs.suid_dumpable = 0

Rationale:

The core dump of a setuid program is more likely to contain sensitive data, as the program itself runs with greater privileges than the user who initiated execution of the program. Disabling the ability for any setuid program to write a core file decreases the risk of unauthorized access of such data.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sysctl_fs_suid_dumpable

References:

hipaa	164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
nist	SI-11(a), SI-11(b)
anssi	R14
pcidss4	3.3.1.1, 3.3.1, 3.3

Remediation Shell script ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

# Comment out any occurrences of fs.suid_dumpable from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do


  # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
  if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

  matching_list=$(grep -P '^(?!#).*[\s]*fs.suid_dumpable.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "fs.suid_dumpable" matches to preserve user data
      sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for fs.suid_dumpable
#
if [[ "$OSCAP_BOOTC_BUILD" != "YES" ]] ; then
    /sbin/sysctl -q -n -w fs.suid_dumpable="0"
fi

#
# If fs.suid_dumpable present in /etc/sysctl.conf, change value to "0"
#	else, add "fs.suid_dumpable = 0" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^fs.suid_dumpable")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "0"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^fs.suid_dumpable\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^fs.suid_dumpable\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*fs.suid_dumpable.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Comment out any occurrences of fs.suid_dumpable from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*fs.suid_dumpable
    replace: '#fs.suid_dumpable'
  loop: '{{ find_sysctl_d.files }}'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

- name: Ensure sysctl fs.suid_dumpable is set to 0
  sysctl:
    name: fs.suid_dumpable
    value: '0'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-SI-11(a)
  - NIST-800-53-SI-11(b)
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_fs_suid_dumpable

Group Enable ExecShield Group contains 1 rule

[ref] ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through sysctl variables kernel.exec-shield and kernel.randomize_va_space. On the latest 64-bit systems, kernel.exec-shield cannot be enabled or disabled with sysctl.

Rule Enable Randomized Layout of Virtual Address Space [ref]

To set the runtime status of the kernel.randomize_va_space kernel parameter, run the following command:

$ sudo sysctl -w kernel.randomize_va_space=2

To make sure that the setting is persistent, add the following line to a file in the directory /etc/sysctl.d:

kernel.randomize_va_space = 2

Rationale:

Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space

References:

cui	3.1.7
disa	CCI-000366, CCI-002824
hipaa	164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
nerc-cip	CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4
nist	SC-30, SC-30(2), CM-6(a)
pcidss	Req-2.2.1
os-srg	SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227
app-srg-ctr	SRG-APP-000450-CTR-001105
anssi	R9
pcidss4	3.3.1.1, 3.3.1, 3.3

Remediation Shell script ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

# Comment out any occurrences of kernel.randomize_va_space from /etc/sysctl.d/*.conf files

for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do


  # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
  if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

  matching_list=$(grep -P '^(?!#).*[\s]*kernel.randomize_va_space.*$' $f | uniq )
  if ! test -z "$matching_list"; then
    while IFS= read -r entry; do
      escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
      # comment out "kernel.randomize_va_space" matches to preserve user data
      sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
    done <<< "$matching_list"
  fi
done

#
# Set sysctl config file which to save the desired value
#

SYSCONFIG_FILE="/etc/sysctl.conf"


#
# Set runtime for kernel.randomize_va_space
#
if [[ "$OSCAP_BOOTC_BUILD" != "YES" ]] ; then
    /sbin/sysctl -q -n -w kernel.randomize_va_space="2"
fi

#
# If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
#	else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
#

# Strip any search characters in the key arg so that the key can be replaced without
# adding any search characters to the config file.
stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.randomize_va_space")

# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$stripped_key" "2"

# If the key exists, change it. Otherwise, add it to the config_file.
# We search for the key string followed by a word boundary (matched by \>),
# so if we search for 'setting', 'setting2' won't match.
if LC_ALL=C grep -q -m 1 -i -e "^kernel.randomize_va_space\\>" "${SYSCONFIG_FILE}"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^kernel.randomize_va_space\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
else
    if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
    fi
    printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	medium
Reboot:	true
Strategy:	disable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: List /etc/sysctl.d/*.conf files
  find:
    paths:
    - /etc/sysctl.d/
    - /run/sysctl.d/
    - /usr/local/lib/sysctl.d/
    - /usr/lib/sysctl.d/
    contains: ^[\s]*kernel.randomize_va_space.*$
    patterns: '*.conf'
    file_type: any
  register: find_sysctl_d
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Comment out any occurrences of kernel.randomize_va_space from config files
  replace:
    path: '{{ item.path }}'
    regexp: ^[\s]*kernel.randomize_va_space
    replace: '#kernel.randomize_va_space'
  loop: '{{ find_sysctl_d.files }}'
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

- name: Ensure sysctl kernel.randomize_va_space is set to 2
  sysctl:
    name: kernel.randomize_va_space
    value: '2'
    sysctl_file: /etc/sysctl.conf
    state: present
    reload: true
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.1.7
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-30
  - NIST-800-53-SC-30(2)
  - PCI-DSS-Req-2.2.1
  - PCI-DSSv4-3.3
  - PCI-DSSv4-3.3.1
  - PCI-DSSv4-3.3.1.1
  - disable_strategy
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
  - sysctl_kernel_randomize_va_space

Group Services Group contains 6 groups and 15 rules

[ref] The best protection against vulnerable software is running less software. This section describes how to review the software which Debian 12 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Debian 12 system and provides guidance about which ones can be safely disabled.

Debian 12 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Debian 12 systems, it is highly recommended to select the minimal packages and then build up the system from there.

Group APT service configuration Group contains 2 rules

[ref] The apt service manage the package management and update of the whole system. Its configuration need to be properly defined to ensure efficient security updates, packages and repository authentication and proper lifecycle management.

Rule Disable unauthenticated repositories in APT configuration [ref]

Unauthenticated repositories should not be used for updates.

Rationale:

Repositories hosts all packages that will be intsalled on the system during update. If a repository is not authenticated, the associated packages can't be trusted, and then should not be installed localy.

Severity:

unknown

Rule ID:

xccdf_org.ssgproject.content_rule_apt_conf_disallow_unauthenticated

References:

disa	CCI-003992
os-srg	SRG-OS-000366-GPOS-00153

Rule Ensure that official distribution repositories are used [ref]
Check that official Debian repositories, including security repository, are configured in apt.
Rationale:	The Debian distribution deliver DSA (Debian Security Announce), through the official Debian security repository, to correct various vulnerabilities impacting the Debian packages. Using the official repositories is the best way to ensure that the Debian updates are integrated soon enough.
Severity:	unknown
Rule ID:	xccdf_org.ssgproject.content_rule_apt_sources_list_official

Group Cron and At Daemons Group contains 1 rule

[ref] The cron and at services are used to allow commands to be executed at a later time. The cron service is required by almost all systems to perform necessary maintenance tasks, while at may or may not be required on a given system. Both daemons should be configured defensively.

Rule Install the cron service [ref]

The Cron service should be installed.

Rationale:

The cron service allow periodic job execution, needed for almost all administrative tasks and services (software update, log rotating, etc.). Access to cron service should be restricted to administrative accounts only.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_package_cron_installed

References:

cis-csc	11, 14, 3, 9
cobit5	BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
disa	CCI-000366
hipaa	164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
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
nist	CM-6(a)
nist-csf	PR.IP-1, PR.PT-3
os-srg	SRG-OS-000480-GPOS-00227

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

DEBIAN_FRONTEND=noninteractive apt-get install -y "cron"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation OSBuild Blueprint snippet ⇲


[[packages]]
name = "cron"
version = "*"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_cron_installed

- name: Ensure cron is installed
  package:
    name: cron
    state: present
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_cron_installed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include install_cron

class install_cron {
  package { 'cron':
    ensure => 'installed',
  }
}

Group Deprecated services Group contains 5 rules

[ref] Some deprecated software services impact the overall system security due to their behavior (leak of confidentiality in network exchange, usage as uncontrolled communication channel, risk associated with the service due to its old age, etc.

Rule Uninstall the inet-based telnet server [ref]

The inet-based telnet daemon should be uninstalled.

Rationale:

telnet allows clear text communications, and does not protect any data transmission between client and server. Any confidential data can be listened and no integrity checking is made.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_package_inetutils-telnetd_removed

References:

cis-csc	11, 12, 14, 15, 3, 8, 9
cobit5	APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, 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 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.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist	CM-7(a), CM-7(b), CM-6(a)
nist-csf	PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable


# CAUTION: This remediation script will remove inetutils-telnetd
#	   from the system, and may remove any packages
#	   that depend on inetutils-telnetd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

DEBIAN_FRONTEND=noninteractive apt-get remove -y "inetutils-telnetd"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

- name: Ensure inetutils-telnetd is removed
  package:
    name: inetutils-telnetd
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_inetutils-telnetd_removed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

include remove_inetutils-telnetd

class remove_inetutils-telnetd {
  package { 'inetutils-telnetd':
    ensure => 'purged',
  }
}

Rule Uninstall the nis package [ref]

The support for Yellowpages should not be installed unless it is required.

Rationale:

NIS is the historical SUN service for central account management, more and more replaced by LDAP. NIS does not support efficiently security constraints, ACL, etc. and should not be used.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_package_nis_removed

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable


# CAUTION: This remediation script will remove nis
#	   from the system, and may remove any packages
#	   that depend on nis. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

DEBIAN_FRONTEND=noninteractive apt-get remove -y "nis"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

- name: Ensure nis is removed
  package:
    name: nis
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_nis_removed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

include remove_nis

class remove_nis {
  package { 'nis':
    ensure => 'purged',
  }
}

Rule Uninstall the ntpdate package [ref]

ntpdate is a historical ntp synchronization client for unixes. It sould be uninstalled.

Rationale:

ntpdate is an old not security-compliant ntp client. It should be replaced by modern ntp clients such as ntpd, able to use cryptographic mechanisms integrated in NTP.

Severity:

low

Rule ID: xccdf_org.ssgproject.content_rule_package_ntpdate_removed

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable


# CAUTION: This remediation script will remove ntpdate
#	   from the system, and may remove any packages
#	   that depend on ntpdate. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

DEBIAN_FRONTEND=noninteractive apt-get remove -y "ntpdate"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

- name: Ensure ntpdate is removed
  package:
    name: ntpdate
    state: absent
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - package_ntpdate_removed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

include remove_ntpdate

class remove_ntpdate {
  package { 'ntpdate':
    ensure => 'purged',
  }
}

Rule Uninstall the ssl compliant telnet server [ref]

The telnet daemon, even with ssl support, should be uninstalled.

Rationale:

telnet, even with ssl support, should not be installed. When remote shell is required, up-to-date ssh daemon can be used.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_package_telnetd-ssl_removed

References:

cis-csc	11, 12, 14, 15, 3, 8, 9
cobit5	APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, 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 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.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist	CM-7(a), CM-7(b), CM-6(a)
nist-csf	PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable


# CAUTION: This remediation script will remove telnetd-ssl
#	   from the system, and may remove any packages
#	   that depend on telnetd-ssl. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

DEBIAN_FRONTEND=noninteractive apt-get remove -y "telnetd-ssl"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

- name: Ensure telnetd-ssl is removed
  package:
    name: telnetd-ssl
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_telnetd-ssl_removed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

include remove_telnetd-ssl

class remove_telnetd-ssl {
  package { 'telnetd-ssl':
    ensure => 'purged',
  }
}

Rule Uninstall the telnet server [ref]

The telnet daemon should be uninstalled.

Rationale:

telnet allows clear text communications, and does not protect any data transmission between client and server. Any confidential data can be listened and no integrity checking is made.'

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_package_telnetd_removed

References:

cis-csc	11, 12, 14, 15, 3, 8, 9
cobit5	APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, 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 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.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist	CM-7(a), CM-7(b), CM-6(a)
nist-csf	PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable


# CAUTION: This remediation script will remove telnetd
#	   from the system, and may remove any packages
#	   that depend on telnetd. Execute this
#	   remediation AFTER testing on a non-production
#	   system!

DEBIAN_FRONTEND=noninteractive apt-get remove -y "telnetd"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

- name: Ensure telnetd is removed
  package:
    name: telnetd
    state: absent
  tags:
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - disable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_telnetd_removed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	disable

include remove_telnetd

class remove_telnetd {
  package { 'telnetd':
    ensure => 'purged',
  }
}

Group Network Time Protocol Group contains 2 rules

[ref] The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can be used both to ensure that time is consistent among a network of systems, and that their time is consistent with the outside world.

If every system on a network reliably reports the same time, then it is much easier to correlate log messages in case of an attack. In addition, a number of cryptographic protocols (such as Kerberos) use timestamps to prevent certain types of attacks. If your network does not have synchronized time, these protocols may be unreliable or even unusable.

Depending on the specifics of the network, global time accuracy may be just as important as local synchronization, or not very important at all. If your network is connected to the Internet, using a public timeserver (or one provided by your enterprise) provides globally accurate timestamps which may be essential in investigating or responding to an attack which originated outside of your network.

A typical network setup involves a small number of internal systems operating as NTP servers, and the remainder obtaining time information from those internal servers.

There is a choice between the daemons ntpd and chronyd, which are available from the repositories in the ntp and chrony packages respectively.

The default chronyd daemon can work well when external time references are only intermittently accesible, can perform well even when the network is congested for longer periods of time, can usually synchronize the clock faster and with better time accuracy, and quickly adapts to sudden changes in the rate of the clock, for example, due to changes in the temperature of the crystal oscillator. Chronyd should be considered for all systems which are frequently suspended or otherwise intermittently disconnected and reconnected to a network. Mobile and virtual systems for example.

The ntpd NTP daemon fully supports NTP protocol version 4 (RFC 5905), including broadcast, multicast, manycast clients and servers, and the orphan mode. It also supports extra authentication schemes based on public-key cryptography (RFC 5906). The NTP daemon (ntpd) should be considered for systems which are normally kept permanently on. Systems which are required to use broadcast or multicast IP, or to perform authentication of packets with the Autokey protocol, should consider using ntpd.

Refer to https://wiki.debian.org/NTP for more detailed comparison of features of chronyd and ntpd daemon features respectively, and for further guidance how to choose between the two NTP daemons.

The upstream manual pages at https://chrony-project.org/documentation.html for chronyd and http://www.ntp.org for ntpd provide additional information on the capabilities and configuration of each of the NTP daemons.

Rule Install the ntp service [ref]

The ntpd service should be installed.

Rationale:

Time synchronization (using NTP) is required by almost all network and administrative tasks (syslog, cryptographic based services (authentication, etc.), etc.). Ntpd is regulary maintained and updated, supporting security features such as RFC 5906.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_package_ntp_installed

References:

cis-csc	1, 14, 15, 16, 3, 5, 6
cobit5	APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
disa	CCI-000160
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-10.4

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

DEBIAN_FRONTEND=noninteractive apt-get install -y "ntp"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation OSBuild Blueprint snippet ⇲


[[packages]]
name = "ntp"
version = "*"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ntp_installed

- name: Ensure ntp is installed
  package:
    name: ntp
    state: present
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - package_ntp_installed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include install_ntp

class install_ntp {
  package { 'ntp':
    ensure => 'installed',
  }
}

Rule Enable the NTP Daemon [ref]

The ntp service can be enabled with the following command:

$ sudo systemctl enable ntp.service

Rationale:

Enabling the ntp service ensures that the ntp service will be running and that the system will synchronize its time to any servers specified. This is important whether the system is configured to be a client (and synchronize only its own clock) or it is also acting as an NTP server to other systems. Synchronizing time is essential for authentication services such as Kerberos, but it is also important for maintaining accurate logs and auditing possible security breaches.

The NTP daemon offers all of the functionality of ntpdate, which is now deprecated.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_service_ntp_enabled

References:

cis-csc	1, 14, 15, 16, 3, 5, 6
cobit5	APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
disa	CCI-000160
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), AU-8(1)(a)
nist-csf	PR.PT-1
pcidss	Req-10.4
pcidss4	10.6.1, 10.6

Remediation OSBuild Blueprint snippet ⇲


[customizations.services]
enabled = ["ntp"]

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4
  - PCI-DSSv4-10.6
  - PCI-DSSv4-10.6.1
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_ntp_enabled

- name: Enable the NTP Daemon - Enable service ntp
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable the NTP Daemon - Enable Service ntp
    ansible.builtin.systemd:
      name: ntp
      enabled: true
      state: started
      masked: false
    when:
    - '"ntp" in ansible_facts.packages'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"ntp" in ansible_facts.packages'
  tags:
  - NIST-800-53-AU-8(1)(a)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.4
  - PCI-DSSv4-10.6
  - PCI-DSSv4-10.6.1
  - enable_strategy
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - service_ntp_enabled

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include enable_ntp

class enable_ntp {
  service {'ntp':
    enable => true,
    ensure => 'running',
  }
}

Group SSH Server Group contains 1 group and 5 rules

[ref] The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called sshd and provided by the RPM package openssh-server.

Group Configure OpenSSH Server if Necessary Group contains 5 rules

[ref] If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file /etc/ssh/sshd_config. The following recommendations can be applied to this file. See the sshd_config(5) man page for more detailed information.

Rule Set SSH Client Alive Count Max to zero [ref]

The SSH server sends at most ClientAliveCountMax messages during a SSH session and waits for a response from the SSH client. The option ClientAliveInterval configures timeout after each ClientAliveCountMax message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. To ensure the SSH timeout occurs precisely when the ClientAliveInterval is set, set the ClientAliveCountMax to value of 0 in /etc/ssh/sshd_config:

Rationale:

This ensures a user login will be terminated as soon as the ClientAliveInterval is reached.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sshd_set_keepalive_0

References:

cis-csc	1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis	5.5.6
cobit5	APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui	3.1.11
disa	CCI-000879, CCI-001133, CCI-002361
hipaa	164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
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, 4.3.4.3.3
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.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, 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 R2.2.3, 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-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csf	DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidss	Req-8.1.8
os-srg	SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "ClientAliveCountMax 0" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive_0

- name: Set SSH Client Alive Count Max to zero
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveCountMax\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveCountMax\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveCountMax\s+
      line: ClientAliveCountMax 0
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_keepalive_0

Rule Set SSH Client Alive Interval [ref]

SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out.

To set this timeout interval, edit the following line in /etc/ssh/sshd_config as follows:

ClientAliveInterval 300

The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600.

If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in /etc/ssh/sshd_config. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle.

Warning: SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration.

Warning: Following conditions may prevent the SSH session to time out:

Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens.
Any scp or sftp activity by the same user to the host resets the timeout.

Rationale:

Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout

References:

cis-csc	1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis	5.5.6
cobit5	APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui	3.1.11
disa	CCI-001133, CCI-002361, CCI-002891
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, 4.3.4.3.3
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.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, 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 R2.2.3, 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	CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csf	DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidss	Req-8.1.8
os-srg	SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175
pcidss4	8.2.8, 8.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

sshd_idle_timeout_value='300'



if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_idle_timeout
- name: XCCDF Value sshd_idle_timeout_value # promote to variable
  set_fact:
    sshd_idle_timeout_value: !!str 300
  tags:
    - always

- name: Set SSH Client Alive Interval
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveInterval\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveInterval\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*ClientAliveInterval\s+
      line: ClientAliveInterval {{ sshd_idle_timeout_value }}
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.11
  - NIST-800-53-AC-12
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-2(5)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SC-10
  - PCI-DSS-Req-8.1.8
  - PCI-DSSv4-8.2
  - PCI-DSSv4-8.2.8
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_set_idle_timeout

Rule Allow Only SSH Protocol 2 [ref]

Only SSH protocol version 2 connections should be permitted. The default setting in /etc/ssh/sshd_config is correct, and can be verified by ensuring that the following line appears:

Protocol 2

Warning: As of openssh-server version 7.4 and above, the only protocol supported is version 2, and line

Protocol 2

in /etc/ssh/sshd_config is not necessary.

Rationale:

SSH protocol version 1 is an insecure implementation of the SSH protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_sshd_allow_only_protocol2

References:

cis-csc	1, 12, 15, 16, 5, 8
cjis	5.5.6
cobit5	APO13.01, DSS01.04, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui	3.1.13, 3.5.4
disa	CCI-000197, CCI-000366
hipaa	164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
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 1.13, 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 2.6, 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
ism	0487, 1449, 1506
iso27001-2013	A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.18.1.4, A.6.2.1, A.6.2.2, 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 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1
nist	CM-6(a), AC-17(a), AC-17(2), IA-5(1)(c), SC-13, MA-4(6)
nist-csf	PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7, PR.PT-4
os-srg	SRG-OS-000074-GPOS-00042, SRG-OS-000480-GPOS-00227

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*Protocol\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "Protocol 2" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.13
  - NIST-800-171-3.5.4
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-13
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sshd_allow_only_protocol2

- name: Allow Only SSH Protocol 2
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*Protocol\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*Protocol\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*Protocol\s+
      line: Protocol 2
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.13
  - NIST-800-171-3.5.4
  - NIST-800-53-AC-17(2)
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-IA-5(1)(c)
  - NIST-800-53-MA-4(6)
  - NIST-800-53-SC-13
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sshd_allow_only_protocol2

Rule Disable SSH Access via Empty Passwords [ref]

Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for PermitEmptyPasswords.
To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in /etc/ssh/sshd_config:

PermitEmptyPasswords no

Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.

Rationale:

Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.

Severity:

high

Rule ID: xccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords

References:

cis-csc	11, 12, 13, 14, 15, 16, 18, 3, 5, 9
cjis	5.5.6
cobit5	APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06
cui	3.1.1, 3.1.5
disa	CCI-000766, CCI-000366
hipaa	164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009	4.3.3.2.2, 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 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.12.5.1, A.12.6.2, 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.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist	AC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csf	PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3
ospp	FIA_UAU.1
pcidss	Req-2.2.4
os-srg	SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PermitEmptyPasswords no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_empty_passwords

- name: Disable SSH Access via Empty Passwords
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitEmptyPasswords\s+
      line: PermitEmptyPasswords no
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-17(a)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_empty_passwords

Rule Disable SSH Root Login [ref]

The root user should never be allowed to login to a system directly over a network. To disable root login via SSH, add or correct the following line in /etc/ssh/sshd_config:

PermitRootLogin no

Rationale:

Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_sshd_disable_root_login

References:

cis-csc	1, 11, 12, 13, 14, 15, 16, 18, 3, 5
cjis	5.5.6
cobit5	APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10
cui	3.1.1, 3.1.5
disa	CCI-000366, CCI-004045
hipaa	164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009	4.3.3.2.2, 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
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 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 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, 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-6(2), AC-17(a), IA-2, IA-2(5), CM-7(a), CM-7(b), CM-6(a)
nist-csf	PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3
ospp	FAU_GEN.1
pcidss	Req-2.2.4
os-srg	SRG-OS-000109-GPOS-00056, SRG-OS-000480-GPOS-00227
app-srg-ctr	SRG-APP-000148-CTR-000335, SRG-APP-000190-CTR-000500
anssi	R33
pcidss4	2.2.6, 2.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

if [ -e "/etc/ssh/sshd_config" ] ; then
    
    LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config"
else
    touch "/etc/ssh/sshd_config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/ssh/sshd_config"

cp "/etc/ssh/sshd_config" "/etc/ssh/sshd_config.bak"
# Insert at the beginning of the file
printf '%s\n' "PermitRootLogin no" > "/etc/ssh/sshd_config"
cat "/etc/ssh/sshd_config.bak" >> "/etc/ssh/sshd_config"
# Clean up after ourselves.
rm "/etc/ssh/sshd_config.bak"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	restrict

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(2)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-2
  - NIST-800-53-IA-2(5)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_root_login

- name: Disable SSH Root Login
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitRootLogin\s+
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitRootLogin\s+
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/ssh/sshd_config
    lineinfile:
      path: /etc/ssh/sshd_config
      create: true
      regexp: (?i)(?i)^\s*PermitRootLogin\s+
      line: PermitRootLogin no
      state: present
      insertbefore: BOF
      validate: /usr/sbin/sshd -t -f %s
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - CJIS-5.5.6
  - NIST-800-171-3.1.1
  - NIST-800-171-3.1.5
  - NIST-800-53-AC-17(a)
  - NIST-800-53-AC-6(2)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-CM-7(a)
  - NIST-800-53-CM-7(b)
  - NIST-800-53-IA-2
  - NIST-800-53-IA-2(5)
  - PCI-DSS-Req-2.2.4
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy
  - sshd_disable_root_login

Group System Accounting with auditd Group contains 2 rules

[ref] The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, auditd has modest disk space requirements, and should not noticeably impact system performance.

NOTE: The Linux Audit daemon auditd can be configured to use the augenrules program to read audit rules files (*.rules) located in /etc/audit/rules.d location and compile them to create the resulting form of the /etc/audit/audit.rules configuration file during the daemon startup (default configuration). Alternatively, the auditd daemon can use the auditctl utility to read audit rules from the /etc/audit/audit.rules configuration file during daemon startup, and load them into the kernel. The expected behavior is configured via the appropriate ExecStartPost directive setting in the /usr/lib/systemd/system/auditd.service configuration file. To instruct the auditd daemon to use the augenrules program to read audit rules (default configuration), use the following setting:

ExecStartPost=-/sbin/augenrules --load

in the /usr/lib/systemd/system/auditd.service configuration file. In order to instruct the auditd daemon to use the auditctl utility to read audit rules, use the following setting:

ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules

in the /usr/lib/systemd/system/auditd.service configuration file. Refer to [Service] section of the /usr/lib/systemd/system/auditd.service configuration file for further details.

Government networks often have substantial auditing requirements and auditd can be configured to meet these requirements. Examining some example audit records demonstrates how the Linux audit system satisfies common requirements. The following example from Red Hat Enterprise Linux 7 Documentation available at

https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages

shows the substantial amount of information captured in a two typical "raw" audit messages, followed by a breakdown of the most important fields. In this example the message is SELinux-related and reports an AVC denial (and the associated system call) that occurred when the Apache HTTP Server attempted to access the /var/www/html/file1 file (labeled with the samba_share_t type):

type=AVC msg=audit(1226874073.147:96): avc:  denied  { getattr } for pid=2465 comm="httpd"
path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file

type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)

msg=audit(1226874073.147:96)
- The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the date command.
{ getattr }
- The item in braces indicates the permission that was denied. getattr indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include getattr, read, and write.
comm="httpd"
- The executable that launched the process. The full path of the executable is found in the exe= section of the system call (SYSCALL) message, which in this case, is exe="/usr/sbin/httpd".
path="/var/www/html/file1"
- The path to the object (target) the process attempted to access.
scontext="unconfined_u:system_r:httpd_t:s0"
- The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the httpd_t domain.
tcontext="unconfined_u:object_r:samba_share_t:s0"
- The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of file1. Note: the samba_share_t type is not accessible to processes running in the httpd_t domain.
From the system call (SYSCALL) message, two items are of interest:
- success=no: indicates whether the denial (AVC) was enforced or not. success=no indicates the system call was not successful (SELinux denied access). success=yes indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as initrc_t and kernel_t.
- exe="/usr/sbin/httpd": the full path to the executable that launched the process, which in this case, is exe="/usr/sbin/httpd".

Rule Ensure the audit Subsystem is Installed [ref]

The audit package should be installed.

Rationale:

The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_package_audit_installed

References:

disa	CCI-000133, CCI-001881, CCI-001875, CCI-000154, CCI-001882, CCI-000158, CCI-001914, CCI-000169, CCI-001464, CCI-001878, CCI-001877, CCI-001889, CCI-000135, CCI-002884, CCI-001487, CCI-003938, CCI-000132, CCI-000134, CCI-000172, CCI-000130, CCI-000131, CCI-001879, CCI-001880, CCI-001876, CCI-000159
hipaa	164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b)
nerc-cip	CIP-004-6 R3.3, CIP-007-3 R6.5
nist	AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a)
ospp	FAU_GEN.1
pcidss	Req-10.1
os-srg	SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
anssi	R33, R73
pcidss4	10.2.1, 10.2

Remediation Shell script ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

# Remediation is applicable only in certain platforms
if dpkg-query --show --showformat='${db:Status-Status}
' 'linux-base' 2>/dev/null | grep -q ^installed; then

DEBIAN_FRONTEND=noninteractive apt-get install -y "auditd"

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

Remediation OSBuild Blueprint snippet ⇲


[[packages]]
name = "auditd"
version = "*"

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-53-AC-7(a)
  - NIST-800-53-AU-12(2)
  - NIST-800-53-AU-14
  - NIST-800-53-AU-2(a)
  - NIST-800-53-AU-7(1)
  - NIST-800-53-AU-7(2)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_audit_installed

- name: Ensure auditd is installed
  package:
    name: auditd
    state: present
  when: '"linux-base" in ansible_facts.packages'
  tags:
  - NIST-800-53-AC-7(a)
  - NIST-800-53-AU-12(2)
  - NIST-800-53-AU-14
  - NIST-800-53-AU-2(a)
  - NIST-800-53-AU-7(1)
  - NIST-800-53-AU-7(2)
  - NIST-800-53-CM-6(a)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - package_audit_installed

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include install_auditd

class install_auditd {
  package { 'auditd':
    ensure => 'installed',
  }
}

Rule Enable auditd Service [ref]

The auditd service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The auditd service can be enabled with the following command:

$ sudo systemctl enable auditd.service

Rationale:

Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the auditd service is active ensures audit records generated by the kernel are appropriately recorded.

Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions.

Severity:

medium

Rule ID: xccdf_org.ssgproject.content_rule_service_auditd_enabled

References:

cis-csc	1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis	5.4.1.1
cobit5	APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui	3.3.1, 3.3.2, 3.3.6
disa	CCI-000133, CCI-001881, CCI-001875, CCI-000154, CCI-001882, CCI-000158, CCI-001914, CCI-000169, CCI-001464, CCI-001878, CCI-001877, CCI-001889, CCI-000135, CCI-002884, CCI-001487, CCI-003938, CCI-000132, CCI-004188, CCI-000134, CCI-000172, CCI-000130, CCI-000131, CCI-001879, CCI-001880, CCI-001876
hipaa	164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b)
isa-62443-2009	4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013	SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, 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 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013	A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nerc-cip	CIP-004-6 R3.3, CIP-007-3 R6.5
nist	AC-2(g), AU-3, AU-10, AU-2(d), AU-12(c), AU-14(1), AC-6(9), CM-6(a), SI-4(23)
nist-csf	DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
ospp	FAU_GEN.1
pcidss	Req-10.1
os-srg	SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
app-srg-ctr	SRG-APP-000095-CTR-000170, SRG-APP-000409-CTR-000990, SRG-APP-000508-CTR-001300, SRG-APP-000510-CTR-001310
anssi	R33, R73
pcidss4	10.2.1, 10.2

Remediation OSBuild Blueprint snippet ⇲


[customizations.services]
enabled = ["auditd"]

Remediation Ansible snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.3.2
  - NIST-800-171-3.3.6
  - NIST-800-53-AC-2(g)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-14(1)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-AU-3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-4(23)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_auditd_enabled

- name: Enable auditd Service - Enable service auditd
  block:

  - name: Gather the package facts
    package_facts:
      manager: auto

  - name: Enable auditd Service - Enable Service auditd
    ansible.builtin.systemd:
      name: auditd
      enabled: true
      state: started
      masked: false
    when:
    - '"auditd" in ansible_facts.packages'
  when:
  - '"linux-base" in ansible_facts.packages'
  - '"auditd" in ansible_facts.packages'
  tags:
  - CJIS-5.4.1.1
  - NIST-800-171-3.3.1
  - NIST-800-171-3.3.2
  - NIST-800-171-3.3.6
  - NIST-800-53-AC-2(g)
  - NIST-800-53-AC-6(9)
  - NIST-800-53-AU-10
  - NIST-800-53-AU-12(c)
  - NIST-800-53-AU-14(1)
  - NIST-800-53-AU-2(d)
  - NIST-800-53-AU-3
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SI-4(23)
  - PCI-DSS-Req-10.1
  - PCI-DSSv4-10.2
  - PCI-DSSv4-10.2.1
  - enable_strategy
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - service_auditd_enabled

Remediation Puppet snippet ⇲

Complexity:	low
Disruption:	low
Reboot:	false
Strategy:	enable

include enable_auditd

class enable_auditd {
  service {'auditd':
    enable => true,
    ensure => 'running',
  }
}

Red Hat and Red Hat Enterprise Linux are either registered trademarks or trademarks of Red Hat, Inc. in the United States and other countries. All other names are registered trademarks or trademarks of their respective companies.