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The RHEL 8 SSH public host key files must have mode 0644 or less permissive.


Overview

Finding ID Version Rule ID IA Controls Severity
V-230286 RHEL-08-010480 SV-230286r627750_rule Medium
Description
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
STIG Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide 2022-06-15

Details

Check Text ( C-32955r567604_chk )
Verify the SSH public host key files have mode "0644" or less permissive with the following command:

$ sudo ls -l /etc/ssh/*.pub

-rw-r--r-- 1 root root 618 Nov 28 06:43 ssh_host_dsa_key.pub
-rw-r--r-- 1 root root 347 Nov 28 06:43 ssh_host_key.pub
-rw-r--r-- 1 root root 238 Nov 28 06:43 ssh_host_rsa_key.pub

If any key.pub file has a mode more permissive than "0644", this is a finding.

Note: SSH public key files may be found in other directories on the system depending on the installation.
Fix Text (F-32930r567605_fix)
Change the mode of public host key files under "/etc/ssh" to "0644" with the following command:

$ sudo chmod 0644 /etc/ssh/*key.pub

The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command:

$ sudo systemctl restart sshd.service