Hardcoded password has been found in products such as FortiOS, alternative solutions include to create a password by hashing the MAC address and seed a password creation algorithm. Some vendors like HP for its ILO password could be using this method.
See also
passwd, ssh-keygen, chage, /etc/passwd, Password policy, Passwd (package), mkpasswd, cracklib-check, Password cracking, Phone to sign in, Passkey, htpasswd, chpasswd