Verify Group Who Owns SSH Server config file
Description
To properly set the group owner of /etc/ssh/sshd_config, run the command:
$ sudo chgrp root /etc/ssh/sshd_config
Rationale
Service configuration files enable or disable features of their respective
services that if configured incorrectly can lead to insecure and vulnerable
configurations. Therefore, service configuration files should be owned by the
correct group to prevent unauthorized changes.
Shell script
The following script can be run on the host to remediate the issue.
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
chgrp 0 /etc/ssh/sshd\_config
else
>&2 echo 'Remediation is not applicable, nothing was done'
fi
Ansible playbook
The following playbook can be run with Ansible to remediate the issue.
- name: Test for existence /etc/ssh/sshd\_config
stat:
path: /etc/ssh/sshd\_config
register: file\_exists
when: ansible\_virtualization\_type not in ["docker", "lxc", "openvz", "podman", "container"]
tags:
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure\_strategy
- file\_groupowner\_sshd\_config
- low\_complexity
- low\_disruption
- medium\_severity
- no\_reboot\_needed
- name: Ensure group owner 0 on /etc/ssh/sshd\_config
file:
path: /etc/ssh/sshd\_config
group: '0'
when:
- ansible\_virtualization\_type not in ["docker", "lxc", "openvz", "podman", "container"]
- file\_exists.stat is defined and file\_exists.stat.exists
tags:
- NIST-800-53-AC-17(a)
- NIST-800-53-AC-6(1)
- NIST-800-53-CM-6(a)
- configure\_strategy
- file\_groupowner\_sshd\_config
- low\_complexity
- low\_disruption
- medium\_severity
- no\_reboot\_needed
