AlmaLinux OS 9 SSH private host key files must have mode 0640 or less permissive.

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-269265ALMA-09-020920SV-269265r1050147_ruleCCI-000366medium
Description
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
STIGDate
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide2025-05-22

Details

Check Text (C-269265r1050147_chk)

Verify the SSH private host key files have a mode of "0640" or less permissive with the following command: $ stat -c "%#a %n" /etc/ssh/ssh_host*key 0640 /etc/ssh/ssh_host_ecdsa_key 0640 /etc/ssh/ssh_host_rsa_key If any private host key file has a mode more permissive than "0640", this is a finding.

Fix Text (F-73197r1048172_fix)

Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: $ chmod 0640 /etc/ssh/ssh_host*key Restart the SSH daemon for the changes to take effect: $ systemctl restart sshd.service