Clam AntiVirus ClamAV rebuildpe Heap Overflow Vulnerability

iDefense Security Advisory 10.15.06
http://www.idefense.com/intelligence/vulnerabilities/ 
Oct 15, 2006

I. BACKGROUND

Clam AntiVirus is a multi-platform GPL anti-virus toolkit.  The main
purpose of which is integration into electronic mail servers.  More
information is available from http://clamav.net/ 

II. DESCRIPTION

Remote exploitation of a buffer overflow in Clam AntiVirus allows
attackers to potentially execute arbitrary code or cause a denial of
service condition.

This vulnerability specifically exists within code dealing PE (Portable
Executable) format files. While processing certain PE elements, two
variables can be very large and integer overflow could occur. This would
result in less memory being allocated than was expected by the
programmer and subsequent code would overflow the heap buffer.

III. ANALYSIS

Successful exploitation requires an attacker to send a specially
constructed executable file through a mail gateway or personal anti-
virus client utilizing the ClamAV scanning engine.

IV. DETECTION

iDefense has confirmed this vulnerability on version 0.88.1 and 0.88.4
of ClamAV.  All previous versions are suspected to be vulnerable to this
issue.

V. WORKAROUND

iDefense is not aware of any effective workarounds.

VI. VENDOR RESPONSE

The ClamAV team has addressed this vulnerability within version 0.88.5.

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2006-4182 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org), which standardizes names for 
security problems.

VIII. DISCLOSURE TIMELINE

08/16/2006  Initial vendor notification
08/20/2006  Initial vendor response
10/10/2006  Second vendor notification
10/15/2006  Coordinated public disclosure

IX. CREDIT

The discovery of this vulnerability is credited to Damian Put
. 

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X. LEGAL NOTICES

Copyright =A9 2006 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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