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V-248601

CAT II (Medium)

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

Rule ID

SV-248601r991589_rule

STIG

Oracle Linux 8 Security Technical Implementation Guide

Version

V2R8

CCIs

CCI-000366

Discussion

If a public host key file is modified by an unauthorized user, the SSH service may be compromised.

Check Content

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

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