AlmaLinux OS 9 SSH daemon must not allow known hosts authentication.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-269267 | SRG-OS-000480-GPOS-00227 | ALMA-09-021140 | SV-269267r1050149_rule | 2026-02-27 | 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 with the following command:
$ sshd -T | grep ignoreuserknownhosts
ignoreuserknownhosts yes
If the value is returned as "no", this is a finding.
✔️ Fix
Configure the SSH daemon to not allow known hosts authentication.
Add the following line to "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes":
IgnoreUserKnownHosts yes
Alternatively, add the setting to an include file if the line "Include /etc/ssh/sshd_config.d/*.conf" is found at the top of the "/etc/ssh/sshd_config" file:
$ echo 'IgnoreUserKnownHosts yes' > /etc/ssh/sshd_config.d/40-knownhosts.conf
Restart the SSH daemon for the settings to take effect:
$ systemctl restart sshd.service