$ login -n root
    Login incorrect
    login: backdoor
    No home directory specified in password file!
    Logging in with home=/
    #

I think this is supposed to be something like CVE-1999-0113 (or its very recently discovered/disclosed friend CVE-2026-24061). It's the sort of thing you might just know off the top of your head that would be handy for getting into a computer that hasn't been updated in 20 years.