RHEL 9 SSH public host key files must have mode 0644 or less permissive.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258001	SRG-OS-000480-GPOS-00227	RHEL-09-255125	SV-258001r991589_rule	2025-02-27	2

Description
If a public host key file is modified by an unauthorized user, the SSH service may be compromised.

ℹ️ Check
Verify the SSH public host key files have a mode of "0644" or less permissive with the following command: Note: SSH public key files may be found in other directories on the system depending on the installation. $ sudo stat -c "%a %n" /etc/ssh/*.pub 644 /etc/ssh/ssh_host_dsa_key.pub 644 /etc/ssh/ssh_host_ecdsa_key.pub 644 /etc/ssh/ssh_host_ed25519_key.pub 644 /etc/ssh/ssh_host_rsa_key.pub If any key.pub file has a mode more permissive than "0644", this is a finding.

ℹ️ Check

Verify the SSH public host key files have a mode of "0644" or less permissive with the following command: Note: SSH public key files may be found in other directories on the system depending on the installation. $ sudo stat -c "%a %n" /etc/ssh/*.pub 644 /etc/ssh/ssh_host_dsa_key.pub 644 /etc/ssh/ssh_host_ecdsa_key.pub 644 /etc/ssh/ssh_host_ed25519_key.pub 644 /etc/ssh/ssh_host_rsa_key.pub If any key.pub file has a mode more permissive than "0644", this is a finding.

✔️ Fix
Change the mode of public host key files under "/etc/ssh" to "0644" with the following command: $ sudo chmod 0644 /etc/ssh/*key.pub Restart the SSH daemon for the changes to take effect: $ sudo systemctl restart sshd.service