One of Unix’s greatest exploits is TFTP (Trivial FTP). To test your system for this vulnerability, connect to your system using TFTP and try

get /etc/motd

If you can do this, then most likely anyone can get your password file. TFTP bypasses traditional verification because it is “trivial” in that as long as you know the exact path where you file is located at, the Unix system bypasses the file security check to see if you have permission or not. Disabling TFTP ensures that your system is safe from this kind of attack.