The Oracle Linux operating system must be configured so the SSH private host key files have mode 0640 or less permissive.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-221859 | OL07-00-040420 | SV-221859r991589_rule | Medium |
| Description |
| If an unauthorized user obtains the private SSH host key file, the host could be impersonated. |
| STIG | Date |
| Oracle Linux 7 Security Technical Implementation Guide | 2025-05-08 |
Details
| Check Text (C-23574r880577_chk) |
| Verify the SSH private host key files have mode 0640 or less permissive. The following command will find all SSH private key files on the system and list their modes: # find / -name '*ssh_host*key' | xargs ls -lL -rw-r----- 1 root ssh_keys 112 Apr 1 11:59 ssh_host_dsa_key -rw-r----- 1 root ssh_keys 202 Apr 1 11:59 ssh_host_key -rw-r----- 1 root ssh_keys 352 Apr 1 11:59 ssh_host_rsa_key If any file has a mode more permissive than 0640, this is a finding. |
| Fix Text (F-23563r880578_fix) |
| Configure the mode of SSH private host key files under "/etc/ssh" to "0640" with the following command: # chmod 0640 /path/to/file/ssh_host*key |