Mac OS X 10.4.3 up to 10.4.6, when loginwindow uses the "Name and password" setting, and the "Show the Restart, Sleep, and Shut Down button…

Mac OS X 10.4.3 up to 10.4.6, when loginwindow uses the "Name and password" setting, and the "Show the Restart, Sleep, and Shut Down buttons" option is disabled, allows users with physical access to bypass login and reboot the system by entering ">restart", ">power", or ">shutdown" sequences after the username.