upstart calls sulogin to start a root shell. sulogin does not prompt for a password when root doesn't have a password. root doesn't have a password on Ubuntu as Ubuntu uses sudo for administration.
** Changed in: upstart (Ubuntu) Sourcepackagename: upstart => sysvinit -- on fscheck a root shell is presented without password https://launchpad.net/bugs/66001 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
