TOSS 5 SSH public host key files must have mode 0644 or less permissive.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-282710SRG-OS-000480-GPOS-00227TOSS-05-000254SV-282710r1201371_rule2026-04-011

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 using 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" using 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