Information
The automatic login feature saves a user's system access credentials and bypasses the login screen, instead the system automatically loads to the user's desktop screen.
Rationale:
Disabling automatic login decreases the likelihood of an unauthorized person gaining access to a system.
Impact:
If Automatic login is not disabled an unauthorized user could login without supplying a user password or credential.
Solution
Perform the following to set automatic login to off:
Graphical Method:
Open System Preferences
Select Users & Groups
Click the lock to authenticate
Select Login Options
Select Automatic login and set it to Off
Terminal Method:
Run the following command to disable automatic login:
$ sudo defaults delete /Library/Preferences/com.apple.loginwindow autoLoginUser