Verify Group Who Owns Backup group File

Docs > Datadog Security > OOTB Rules > Verify Group Who Owns Backup group File

Description

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

$ sudo chgrp root /etc/group-

Rationale

The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Remediation

Shell script

The following script can be run on the host to remediate the issue.

#!/bin/bash

if getent group "0" >/dev/null 2>&1; then
  newgroup="0"
fi
if [[ -z ${newgroup} ]]; then
  echo "0 is not a defined group on the system"
  exit 1
fi
chgrp $newgroup /etc/group-

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: Set the file_groupowner_backup_etc_group_newgroup variable if represented
    by gid
  set_fact:
    file_groupowner_backup_etc_group_newgroup: '0'
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

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

- name: Ensure group owner on /etc/group-
  file:
    path: /etc/group-
    group: '{{ file_groupowner_backup_etc_group_newgroup }}'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_groupowner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed