[30630] in bugtraq

home help back first fref pref prev next nref lref last post

Re: Trillian Remote DoS

daemon@ATHENA.MIT.EDU (Erik Jacobson)
Tue Jul 8 12:55:31 2003

From: "Erik Jacobson" <uhlume@hotmail.com>
To: bugtraq@securityfocus.com
Date: Tue, 08 Jul 2003 08:19:18 -0400
Mime-Version: 1.0
Content-Type: text/plain; format=flowed
Message-ID: <BAY8-F86dGSyMp69YDq000168b4@hotmail.com>

Did you even bother notifying the vendor?  Or crediting the person who 
originally discovered this?  Unless you happen to be him, although it 
doesn't appear so from your site.

Anyway, this bug has been known about for a while, and is fixed in the next 
version.  Unfortunately they aren't releasing a patch before then.

----Original Message Follows----
From: flur <flur@flurnet.org>
To: bugtraq Security List <bugtraq@securityfocus.com>
Subject: Trillian Remote DoS
Date: Fri, 04 Jul 2003 18:09:55 -0400

Application:    Trillian
Developer(s):   Cerulean Studios (http://www.trillian.cc)
Scope:          Remote DoS & Possible Exploit
Tested on:      Trillian 1.0 Pro, 0.74 Freeware

It is possible to crash Trillian by sending a corrupt 'TypingUser' message. 
Replacing any of the characters in 'TypingUser' will cause Trillian to 
crash. If more then 10 characters are used, or if the colon is omitted, 
Trillian will not crash. The crash occurs due to a function within msn.dll 
for both Trillian 1 and 0.74. This may be exploitable further.

In order to exploit this condition, no code is necessary- simply hex edit a  
messenger client, replacing the string 'TypingUser' with any other string of 
the same length (or simply changing a letter or two). However this method of 
exploitation does break Microsoft's EULA/TOS, and you are not encouraged to 
utilize a broken client in this way except in an educational context. This 
'hack' also prevents other non-trillian Messenger clients from detecting 
when a user is typing.

Crash Summary:

MOV ECX,DWORD PTR DS:[EDX]  ; EDX is uninitialized

The crash looks something like this:

Instruction at 0x####8826 referenced memory at 0x00000000

Sample TCP session to crash Trillian:

MIME-Version: 1.0
Content-Type: text/x-msmsgscontrol
TypingXxxx: attacker@blah.com

Our preliminary tests showed that memory was not manipulable, and thus this 
bug is not exploitable further then DoS. Please make further research public 
if you discover otherwise.

_________________________________________________________________
MSN 8 helps eliminate e-mail viruses. Get 2 months FREE*.  
http://join.msn.com/?page=features/virus


home help back first fref pref prev next nref lref last post