You should make sure that all users have a valid password.
Become superuser or assume an equivalent role.
Display all users who have no passwords by using the logins command.
# logins -p |
The -p option displays a list of users with no passwords. The logins command uses the local /etc/passwd file and the name service password databases to obtain a user's login status.
The following example shows that the user pmorph does not have a password.
# logins -p pmorph 501 other 1 Polly Morph # |