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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258000	RHEL-09-255120	SV-258000r925987_rule		Medium

Description
If an unauthorized user obtains the private SSH host key file, the host could be impersonated.

STIG	Date
Red Hat Enterprise Linux 9 Security Technical Implementation Guide	2023-12-01

Details

Check Text ( C-61741r925985_chk )
Verify the SSH private host key files have a mode of "0640" or less permissive with the following command: $ ls -l /etc/ssh/*_key 640 /etc/ssh/ssh_host_dsa_key 640 /etc/ssh/ssh_host_ecdsa_key 640 /etc/ssh/ssh_host_ed25519_key 640 /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-61665r925986_fix)
Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: $ sudo chmod 0640 /etc/ssh/ssh_host*key Restart the SSH daemon for the changes to take effect: $ sudo systemctl restart sshd.service