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 | CCI-000366 | 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-221859r991589_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