Vulnerability Discussion

Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes.

Check

Verify the group ownership of "/etc/ssh/sshd_config" and any "/etc/ssh/sshd_config.d/*.conf" files with the following command:

$ find /etc/ssh/sshd_config /etc/ssh/sshd_config.d -exec stat -c "%G %n" {} \;

root /etc/ssh/sshd_config
root /etc/ssh/sshd_config.d
root /etc/ssh/sshd_config.d/40-stig.conf
root /etc/ssh/sshd_config.d/50-redhat.conf
root /etc/ssh/sshd_config.d/clientalive.conf

If any of the files do not have a group owner of "root", this is a finding.

Fix

Configure the SSHD config files to be group-owned by root with the following command:

$ chgrp root /etc/ssh/sshd_config /etc/ssh/sshd_config.d/*.conf