The TOSS SSH daemon must not allow authentication using known host's authentication.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-252942 | TOSS-04-010400 | SV-252942r991589_rule | CCI-000366 | medium |
| Description | ||||
| Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere. | ||||
| STIG | Date | |||
| Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-252942r991589_chk)
Verify the SSH daemon does not allow authentication using known host's authentication with the following command:
$ sudo grep -i IgnoreUserKnownHosts /etc/ssh/sshd_config
IgnoreUserKnownHosts yes
If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding.
Fix Text (F-56345r824149_fix)
Configure the SSH daemon to not allow authentication using known host's authentication.
Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes":
IgnoreUserKnownHosts yes
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