Ensure gpgcheck Enabled for Local Packages

An XCCDF Rule

Description

yum should be configured to verify the signature(s) of local packages prior to installation. To configure yum to verify signatures of local packages, set the localpkg_gpgcheck to 1 in /etc/yum.conf.

Rationale

Changes to any software components can have significant effects to the overall security of the operating system. This requirement ensures the software has not been tampered and has been provided by a trusted vendor.

Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization.

ID: xccdf_org.ssgproject.content_rule_ensure_gpgcheck_local_packages
Severity: High
References: BP28(R15)

11 3 9

BAI10.01 BAI10.02 BAI10.03 BAI10.05

3.4.8

CCI-001749

164.308(a)(1)(ii)(D) 164.312(b) 164.312(c)(1) 164.312(c)(2) 164.312(e)(2)(i)

4.3.4.3.2 4.3.4.3.3

SR 7.6

A.12.1.2 A.12.5.1 A.12.6.2 A.14.2.2 A.14.2.3 A.14.2.4

CM-11(a) CM-11(b) CM-5(3) CM-6(a) SA-12 SA-12(10)

PR.IP-1

FPT_TUD_EXT.1 FPT_TUD_EXT.2

SRG-OS-000366-GPOS-00153
Updated: about 1 year ago

# Remediation is applicable only in certain platforms
if rpm --quiet -q yum; then

# 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=$(sed 's/[\^=\$,;+]*//g' <<< "^localpkg_gpgcheck")
# shellcheck disable=SC2059
printf -v formatted_output "%s = %s" "$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 "^localpkg_gpgcheck\\>" "/etc/yum.conf"; then
    escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
    LC_ALL=C sed -i --follow-symlinks "s/^localpkg_gpgcheck\\>.*/$escaped_formatted_output/gi" "/etc/yum.conf"
else
    if [[ -s "/etc/yum.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/yum.conf" || true)" ]]; then
        LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/yum.conf"
    fi
    printf '%s\n' "$formatted_output" >> "/etc/yum.conf"
fi

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

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-11(a)  - NIST-800-53-CM-11(b)
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SA-12
  - NIST-800-53-SA-12(10)
  - ensure_gpgcheck_local_packages
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed
  - unknown_strategy

- name: Ensure GPG check Enabled for Local Packages (yum)
  block:

  - name: Check stats of yum
    stat:
      path: /etc/yum.conf
    register: pkg

  - name: Check if config file of yum is a symlink
    ansible.builtin.set_fact:
      pkg_config_file_symlink: '{{ pkg.stat.lnk_target if pkg.stat.lnk_target is match("^/.*")
        else "/etc/yum.conf" | dirname ~ "/" ~ pkg.stat.lnk_target }}'
    when: pkg.stat.lnk_target is defined

  - name: Ensure GPG check Enabled for Local Packages (yum)
    ini_file:
      dest: '{{ pkg_config_file_symlink |  default("/etc/yum.conf") }}'
      section: main
      option: localpkg_gpgcheck
      value: 1
      no_extra_spaces: true
      create: true
  when: '"yum" in ansible_facts.packages'
  tags:
  - NIST-800-171-3.4.8
  - NIST-800-53-CM-11(a)
  - NIST-800-53-CM-11(b)
  - NIST-800-53-CM-5(3)
  - NIST-800-53-CM-6(a)
  - NIST-800-53-SA-12
  - NIST-800-53-SA-12(10)
  - ensure_gpgcheck_local_packages
  - high_severity
  - low_complexity
  - medium_disruption
  - no_reboot_needed
  - unknown_strategy

Ensure gpgcheck Enabled for Local Packages

Description

Rationale

Remediation - Shell Script

Remediation - Ansible