Trillian Can By Crashed By Remote Users Sending a Malformed 'TypingUser' Message
SecurityTracker Alert ID: 1007119|
SecurityTracker URL: http://securitytracker.com/id/1007119
(Links to External Site)
Date: Jul 7 2003
Denial of service via network|
Version(s): 1.0 Pro, 0.74|
A denial of service vulnerability was reported in Trillian. A remote user can cause the client to crash.|
It is reported that a remote user can send a malformed 'TypingUser' message that replaces any of the characters in 'TypingUser' to trigger a crash within msn.dll.
A remote user can cause a target user's Trillian client to crash.|
No solution was available at the time of this entry.|
Vendor URL: www.trillian.cc/ (Links to External Site)
Exception handling error|
Source Message Contents
Date: Fri, 04 Jul 2003 18:09:55 -0400|
Subject: Trillian Remote DoS
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.
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:
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.
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KEY ID 0x8C2C37C4 (pgp.mit.edu) RSA-CAST 2048/2048
1876 B762 F909 91EB 0C02 C06B 83FF E6C5 8C2C 37C4