Vulnerability Discussion

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

Check

Verify the SUSE operating system SSH daemon 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 'ssh_host*key.pub' -exec stat -c "%a %n" {} \;

644 /etc/ssh/ssh_host_rsa_key.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

If any file has a mode more permissive than "0644", this is a finding.

Fix

Configure the SUSE operating system SSH daemon 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.

Change the mode of public host key files under "/etc/ssh" to "0644" with the following command:

> sudo chmod 0644 /etc/ssh/ssh_host*key.pub