The SUSE operating system SSH daemon public host key files must have mode 0644 or less permissive.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-235008	SLES-15-040240	SV-235008r622137_rule		Medium

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

STIG	Date
SUSE Linux Enterprise Server 15 Security Technical Implementation Guide	2021-11-30

Details

Check Text ( C-38196r619293_chk )
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.

Check Text ( C-38196r619293_chk )

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 Text (F-38159r619294_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