The TOSS 5 SSH daemon must not allow known hosts authentication.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-282712 | SRG-OS-000480-GPOS-00227 | TOSS-05-000258 | SV-282712r1201589_rule | 2026-04-01 | 1 |
Description
Configuring the IgnoreUserKnownHosts setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
ℹ️ Check
Verify the SSH daemon does not allow known hosts authentication using the following command:
$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*ignoreuserknownhosts'
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 known hosts authentication.
Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes":
IgnoreUserKnownHosts yes
Restart the SSH service for changes to take effect:
$ sudo systemctl restart sshd.service