Cerulean Studios Trillian UTF-8 Word Wrap Heap Overflow Vulnerability

iDefense Security Advisory 06.18.07
http://labs.idefense.com/intelligence/vulnerabilities/ 
Jun 18, 2007

I. BACKGROUND

Trillian is a multi-protocol chat application that supports IRC, ICQ,
AIM and MSN protocols. More information can be found on the vendor's
site at the following URL.

http://www.ceruleanstudios.com/learn 

II. DESCRIPTION

Remote exploitation of a heap overflow vulnerability in Cerulean Studios
Trillian Instant Messenger could allow attackers to execute arbitrary
code as the currently logged on user.

The vulnerability specifically exists due to improper handling of UTF-8
sequences. When word-wrapping UTF-8 text, the window width is
improperly used as a buffer size value. As such, heap corruption can
occur leading to a potentially exploitable condition.

III. ANALYSIS

Exploitation of this vulnerability could allow remote attackers to
execute arbitrary code with the credentials of the currently logged on
user.

Exploitation occurs simply by viewing a malicious message that contains
a specially constructed UTF-8 string.

The MSN protocol is a known attack vector for this vulnerability.
However, exploitation could potentially occur using any supported
protocol.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Cerulean
Studios Trillian 3.1.5.1. Previous versions are suspected to be
vulnerable.

V. WORKAROUND

iDefense is currently unaware of any effective workaround for this
issue.

VI. VENDOR RESPONSE

The Cerulean Studios team has addressed this vulnerability by releasing
version 3.1.6.0 of Trillian. More information is available at the
Cerulean Studios Blog via the following URL.

http://blog.ceruleanstudios.com/?p=150 

VII. CVE INFORMATION

A Mitre Corp. Common Vulnerabilities and Exposures (CVE) number has not
been assigned yet.

VIII. DISCLOSURE TIMELINE

05/04/2007  Initial vendor notification
05/04/2007  Initial vendor response
06/18/2007  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to iDefense by www.BlurredLogic.com. 

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X. LEGAL NOTICES

Copyright =A9 2007 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
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