The TOSS SSH daemon must not allow authentication using known host's authentication.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-252942 | SRG-OS-000480-GPOS-00227 | TOSS-04-010400 | SV-252942r991589_rule | 2026-02-19 | 2 |
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.
ℹ️ Check
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
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