Title

RHEL 9 SSH public host key files must have mode 0644 or less permissive. (Cat II impact)

Discussion

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

Check Content

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 Text

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

Additional Identifiers

Rule ID: SV-258001r925990_rule

Vulnerability ID: V-258001

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

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