From: dendler at idefense.com (David Endler)
Subject: RE: iDefense Security Advisory

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

While it may seem rather obvious, this was not an iDEFENSE advisory. 
gobbles@...mail.com is not an employee, contractor, contributor, nor
representative of iDEFENSE in any way.  All legitimate iDEFENSE
advisories are located at http://www.idefense.com/advisory and are
properly PGP signed when sent over email.

Thanks,

- -dave

David Endler, CISSP
Director, Technical Intelligence
iDEFENSE, Inc.
14151 Newbrook Drive
Suite 100
Chantilly, VA 20151
voice: 703-344-2632
fax: 703-961-1071

dendler@...fense.com
www.idefense.com

> -----Original Message-----
> From: gobbles@...hmail.com [mailto:gobbles@...hmail.com]
> Sent: Thursday, December 12, 2002 6:27 PM
> To: full-disclosure@...ts.netsys.com; bugtraq@...urityfocus.com;
> vulnwatch@...nwatch.org; submissions@...ketstormsecurity.org;
> str@...nibus.dataforce.net; vuln-dev@...urityfocus.com;
> shok@...el.ethereal.net
> Subject: iDefense Security Advisory
> 
> 
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> 
> iDEFENSE Security Advisory 12.13.02:
> http://www.idefense.com/advisory/12.13.02.txt
> Bufferoverflow in 0verkill Server
> December 13, 2002
> 
> I. BACKGROUND
> 
> 0verkill is a client-server 2d deathmatch-like game in ASCII art. 
> It supports free connecting/disconnecting during the game, and 
> runs well on
> modem lines.  Graphics are in 16-color ASCII art with elaborate
> hero animations.  0verkill features 4 different weapons, grenades, 
> invisibility,
> and armor.  The package also contains reaperbot clients, a 
> simple graphics
> editor, and a level editor.  The server portion of 0verkill 
> listens on an
> UDP port (6666 by default).
> 
> 
> II. DESCRIPTION
> 
> Remote explotation of a buffer overflow within the 0verkill 
> server source
> could allow a remote attacker to gain the privilages of 
> whichever user the
> process is running as.  Since there are no authentication 
> measures built
> into the game, this problem can be considered to be PREAUTH*. 
>  This is a
> very serious vulnerability and should be taken seriously.
> 
> The following is a snapshot of the exploit in action.
> 
> deraadt@...s.theos.com:~$ ./0verkillflow -t 5 -h 192.168.0.1 
> -o l -p 6666
> Attacking host 192.168.0.1 (Linux 2.4.20-grsec).
> *GOBBLE*
> id; uname -a
> uid=0(root) gid=0(root) 
> groups=0(root),1(bin),2(daemon),3(sys),4(adm),6(disk),10(wheel)
> Linux spender 2.4.20 #1 Sat Dec 7 13:44:54 EST 2002 i686 unknown
> ^C
> 
> deraadt@...s.theos.com:~$ su -
> Password:
> root@...s.theos.com:~# rm -rf /&
> 
> 
> III. ANALYSIS
> 
> Remote attackers can use this exploit to gain unauthorized 
> access to your
> corporate network if you do not immediately upgrade to the 
> latest version of
> 0verkill.  We have seen evidence of this being exploited in 
> the wild, and
> suggest that ISS and Securityfocus increase the ARIS 
> Threatcon to at least 7.
> 
> Most of our clients have probably already been compromised by 
> this exploit of
> ours, and those who were not running the daemon as root were 
> probably later
> rooted locally by bugs in **Abuse that the author refuses to patch.
> 
> Since this exploit exists in the wild, we will soon send our 
> IDS signatures
> to Max Vision and Martin Roesch so that they may update their 
> IDS systems to
> detect this version of the attack, and this exploit 
> specifically.  Please
> keep in mind that these signatures will not be sufficient for 
> other versions
> of the exploit, and that you may need to upgrade your IDS to a
> better mechanism that is capable of detecting more than specific 
> versions of an
> attack.
> 
> 
> IV. DETECTION
> 
> To detect whether or not you are running a vulnerable version 
> of the 0verkill
> server or not, we suggest that you take the md5sum of the 
> binary.  For example:
> 
> root@...s.theos.com:/usr/src/0verkill-0.16# md5sum server
> 0f210947eec2ead10e00069896d2f4bb  server
> 
> If your server binary has the same checksum as our binary, 
> here at iDefense
> Labs, you are vulnerable to this attack and must immediately 
> upgrade your
> service to the latest version.  We're currently attempting to 
> devise a more
> reliable method to verify whether or not an executable is 
> vulnerable or not,
> but our research scientists are at this time stumped.
> 
> The IDS experts from Sourcefire, ISS, and NFR are currently 
> studying this
> vulnerability and are developing exploits for it, so that 
> they might understand
> all possible methods of exploitation, and accordingly create 
> the proper dynamic
> rules to help you detect all variations of this bug being 
> exploited, instead of
> a single version which ultimately won't help anything.  Once 
> this has been done, you can replay your network traffic 
> through your sensors and watch to see if this has been 
> exploited on your network yet or not.
> 
> 
> V. VENDOR FIX
> 
> We have not been able to contact any of the developers for 
> the software, and at this time there is no fix for the problem.
> 
> 
> VI. CVE INFORMATION
> 
> We have received information from Brian McWilliams which 
> links MITRE to the
> Al Quada terrorist network, and for this reason we will no 
> longer participate
> in any MITRE sponsored programs.
> 
> 
> VII. DISCLOSURE TIMELINE
> 
> 11/20/2002	Issue disclosed to iDEFENSE
> 12/08/2002	Maintainer, Brain (brain@...ax.karlin.mff.cuni.cz),
> 		and NetBSD Security Officer 
> (security-officer@...bsd.org)
> 		notified.
> 12/09/2002	Contacted CERT (cert@...t.org) about the matter.
> 12/10/2002	Attempted to contact CERT again for assistance 
> with contacting
> 		the authors of 0verkill.
> 12/11/2002	iDEFENSE clients notified
> 12/12/2002	Coordinated public disclosure
> 
> VIII. CREDIT
> 
> GOBBLES (GOBBLES@...hmail.com) discovered this vulnerability.
> 
> *By PREAUTH, we mean pre-authentication.
> **Please read our previous advisory on Abuse, which can be found
> here: 	 http://www.idefense.com/advisory/11.01.02.txt
> 
> " Life without CERT is like the Chocolate Factory without 
> Charlie :-( "

-----BEGIN PGP SIGNATURE-----
Version: PGP 8.0
Comment: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x4B0ACC2A

iQA/AwUBPfkxxkrdNYRLCswqEQKEEwCg5SglpcAEpH8sWVV435jVWO1sqi0AoPRF
71oUnPD15dVap17hzCeHrQr3
=UGXc
-----END PGP SIGNATURE-----

Powered by blists - more mailing lists