The Oracle Linux operating system must be configured so that the SSH public host key files have mode 0644 or less permissive.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-221858 | OL07-00-040410 | SV-221858r991589_rule | CCI-000366 | medium |
| Description | ||||
| If a public host key file is modified by an unauthorized user, the SSH service may be compromised. | ||||
| STIG | Date | |||
| Oracle Linux 7 Security Technical Implementation Guide | 2025-05-08 | |||
Details
Check Text (C-221858r991589_chk)
Verify the SSH public host key files have mode 0644 or less permissive.
Note: SSH public key files may be found in other directories on the system depending on the installation.
The following command will find all SSH public key files on the system:
# find /etc/ssh -name '*.pub' -exec ls -lL {} \;
-rw-r--r-- 1 root root 618 Nov 28 06:43 ssh_host_dsa_key.pub
-rw-r--r-- 1 root root 347 Nov 28 06:43 ssh_host_key.pub
-rw-r--r-- 1 root root 238 Nov 28 06:43 ssh_host_rsa_key.pub
If any file has a mode more permissive than 0644, this is a finding.
Fix Text (F-23562r419647_fix)
Note: SSH public key files may be found in other directories on the system depending on the installation.
Change the mode of public host key files under "/etc/ssh" to "0644" with the following command:
# chmod 0644 /etc/ssh/*.key.pub