Ensure SELinux State is Enforcing

An XCCDF Rule

Description

The SELinux state should be set to at system boot time. In the file /etc/selinux/config, add or correct the following line to configure the system to boot into enforcing mode:

SELINUX=

Rationale

Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.

ID: xccdf_org.ssgproject.content_rule_selinux_state
Severity: High
References: BP28(R4) BP28(R66)

1 11 12 13 14 15 16 18 3 4 5 6 8 9

APO01.06 APO11.04 APO13.01 BAI03.05 DSS01.05 DSS03.01 DSS05.02 DSS05.04 DSS05.05 DSS05.07 DSS06.02 DSS06.03 DSS06.06 MEA02.01

3.1.2 3.7.2

CCI-001084 CCI-002165 CCI-002696

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)

4.2.3.4 4.3.3.2.2 4.3.3.3.9 4.3.3.4 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 4.3.4.4.7 4.4.2.1 4.4.2.2 4.4.2.4 4.4.3.3

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 2.10 SR 2.11 SR 2.12 SR 2.2 SR 2.3 SR 2.4 SR 2.5 SR 2.6 SR 2.7 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

A.10.1.1 A.11.1.4 A.11.1.5 A.11.2.1 A.12.1.1 A.12.1.2 A.12.4.1 A.12.4.2 A.12.4.3 A.12.4.4 A.12.7.1 A.13.1.1 A.13.1.2 A.13.1.3 A.13.2.1 A.13.2.2 A.13.2.3 A.13.2.4 A.14.1.2 A.14.1.3 A.6.1.2 A.7.1.1 A.7.1.2 A.7.3.1 A.8.2.2 A.8.2.3 A.9.1.1 A.9.1.2 A.9.2.1 A.9.2.3 A.9.4.1 A.9.4.4 A.9.4.5

CIP-003-8 R5.1.1 CIP-003-8 R5.2 CIP-003-8 R5.3 CIP-004-6 R2.2.3 CIP-004-6 R2.3 CIP-004-6 R3.3 CIP-007-3 R5.1 CIP-007-3 R5.1.2 CIP-007-3 R5.2 CIP-007-3 R5.3.1 CIP-007-3 R5.3.2 CIP-007-3 R5.3.3 CIP-007-3 R6.5

AC-3 AC-3(3)(a) AU-9 SC-7(21)

DE.AE-1 ID.AM-3 PR.AC-4 PR.AC-5 PR.AC-6 PR.DS-5 PR.PT-1 PR.PT-3 PR.PT-4

SRG-OS-000134-GPOS-00068 SRG-OS-000445-GPOS-00199
Updated: about 1 year ago

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then

var_selinux_state='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_selinux_state" use="legacy"/>'

if [ -e "/etc/selinux/config" ] ; then
    
    LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
else
    touch "/etc/selinux/config"
fi
# make sure file has newline at the end
sed -i -e '$a\' "/etc/selinux/config"

cp "/etc/selinux/config" "/etc/selinux/config.bak"
# Insert at the end of the file
printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
# Clean up after ourselves.
rm "/etc/selinux/config.bak"

fixfiles onboot
fixfiles -f relabel

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

- name: XCCDF Value var_selinux_state # promote to variable
  set_fact:
    var_selinux_state: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_selinux_state" use="legacy"/>
  tags:
    - always
- name: Ensure SELinux State is Enforcing
  block:

  - name: Check for duplicate values
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUX=
      state: absent
    check_mode: true
    changed_when: false
    register: dupes

  - name: Deduplicate values from /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUX=
      state: absent
    when: dupes.found is defined and dupes.found > 1

  - name: Insert correct line to /etc/selinux/config
    lineinfile:
      path: /etc/selinux/config
      create: true
      regexp: ^SELINUX=
      line: SELINUX={{ var_selinux_state }}
      state: present
  when: ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  tags:
  - NIST-800-171-3.1.2
  - NIST-800-171-3.7.2
  - NIST-800-53-AC-3
  - NIST-800-53-AC-3(3)(a)
  - NIST-800-53-AU-9
  - NIST-800-53-SC-7(21)
  - high_severity
  - low_complexity
  - low_disruption
  - no_reboot_needed
  - restrict_strategy
  - selinux_state

Ensure SELinux State is Enforcing

Description

Rationale

Remediation - Shell Script

Remediation - Ansible