OL 9 SSH daemon must not allow rhosts authentication.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-271711 | OL09-00-002348 | SV-271711r1091845_rule | CCI-000366 | medium |
| Description | ||||
| SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. | ||||
| STIG | Date | |||
| Oracle Linux 9 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-271711r1091845_chk)
Verify that OL 9 SSH daemon does not allow rhosts authentication with the following command:
$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*ignorerhosts'
IgnoreRhosts 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-75668r1091844_fix)
Configure the SSH daemon to not allow rhosts authentication.
Add the following line to "/etc/ssh/sshd_config" or to a file in "/etc/ssh/sshd_config.d" or uncomment the line and set the value to "yes":
IgnoreRhosts yes
The SSH service must be restarted for changes to take effect:
$ sudo systemctl restart sshd.service