COMMAND
/dev
SYSTEMS AFFECTED
NetBSD, FreeBSD -current, OpenBSD
PROBLEM
Hubert Feyrer found following. In {Free,Net,Open}BSD, any user
can mount a filesystem as long as he owns the mountpoint, and has
appropriate access to the device to mount from. Almost! For the
cd9660 filesystem (and at least on NetBSD, the filecorefs) this
second check was not performed, and any user was able to and
access a CDROM whether /dev/cd0a was accessible to him or not.
SOLUTION
This was fixed in NetBSD on 19980905 by Charles Hannum, the
problem is still present in Free- and OpenBSD as of the time of
this writing.
Note that in OpenBSD only the superuser may mount filesystems by
default. This can be changed by setting the kern.usermount sysctl
to 1. The same goes for FreeBSD. Also, the problem is only
relevant for FreeBSD-current, not -stable or the releases - ie,
2.2.* does not seem vulnerable.