Vulnerability Discussion

Unapproved mechanisms used for authentication to the cryptographic module are not verified; therefore, cannot be relied upon to provide confidentiality or integrity and DOD data may be compromised.

AlmaLinux OS 9 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules.

The key derivation function (KDF) in Kerberos is not FIPS compatible. Ensuring the system does not have any keytab files present prevents system daemons from using Kerberos for authentication. A keytab is a file containing pairs of Kerberos principals and encrypted keys.

FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system.

Check

Verify that AlmaLinux OS 9 prevents system daemons from using Kerberos for authentication with the following command:

$ ls -alR /etc/*.keytab

ls: cannot access '/etc/*.keytab': No such file or directory

If this command produces any "keytab" file(s), this is a finding.

Fix

Configure AlmaLinux OS 9 to prevent system daemons from using Kerberos for authentication.

Remove any files with the .keytab extension from the operating system.

rm -f /etc/*.keytab