Possible SunOS 5.5.1 sulogin vulnerability

Possible hole in sulogin here? Under Solaris 2.5.1 (sparc & x86),
executing /sbin/sulogin from an unprivileged user account dumps you
into what appears to be single-user mode with an ugly warning message
without prompting for the root password. You don't find this with
earlier versions of Solaris (2.5 and lower).

________________________________________________________________

sol251% /sbin/sulogin

*** NO ENTRY FOR root IN PASSWORD FILE! ***

Entering System Maintenance Mode

$

________________________________________________________________

sol25% /sbin/sulogin

Type Ctrl-d to proceed with normal startup,
(or give root password for system maintenance):

________________________________________________________________
Received on Nov 15 1996