Vulnerability in ccdconfig

Niall Smart (rotel@INDIGO.IE)
Wed, 31 Dec 1997 02:02:31 +0000


FreeBSD and NetBSD's ccdconfig doesn't do proper checking of the
argument to -f:

[nsmart@ginseng ~]$ ccdconfig -U -f /dev/mem 2>&1 | strings | grep Charlie
root:iDeLeTeDiT:0:0::0:0:Charlie: No such file or directory

I had to cat /etc/master.passwd in another window to get this to
work though :) So perhaps its not very easily exploitable, but
is worth fixing nonetheless.

This bug was also spotted by and fixed in OpenBSD
some time ago.


* FreeBSD and NetBSD have been notified of the problem and have fixed
it in their source tree's as of yesterday (FreeBSD-current,
FreeBSD-stable, NetBSD-current) Retrieve the patched ccdconfig.c
and compile yourself a new ccdconfig.

* "chmod g-s /sbin/ccdconfig". I can't think of any reason for it to be
sgid kmem.