Kaspersky Antivirus Scan Engine PE File Denial of Service Vulnerability

iDefense Security Advisory 01.05.07
http://labs.idefense.com/intelligence/vulnerabilities/
Jan 05, 2007

I. BACKGROUND

Kaspersky Antivirus is a popular client and gateway virus scanner.  For
more information see their site:

http://www.kaspersky.com/

II. DESCRIPTION

Remote exploitation of a DoS vulnerability in Kaspersky Lab's Antivirus
could allow an attacker to cause a denial of service (DoS) condition.

Kaspersky Antivirus is vulnerable to a DoS condition when processing a
specially crafted PE (portable executable) file. One of the headers in a PE
file is the Optional Windows Header section. This section of the PE header
contains information needed by the Windows linker and loader. An invalid
value for the 'NumberOfRvaAndSizes' field will cause Kaspersky to
repeatedly seek and read from the same section of the file in an endless
loop.

III. ANALYSIS

Exploitation allows attackers to send the scanning engine into an infinite
loop. Further attempts to scan files will be prevented.

Exploitation requires that an attacker sends a specially constructed PE
file through an e-mail gateway or personal anti-virus client using the
Kaspersky scanning engine.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Kaspersky
Labs Antivirus Engine version 6.0 for Windows and 5.5-10 for Linux.
Previous versions may also be affected. Any products that use the scanning
engine are also affected. This includes the Kaspersky mail gateway scanner.

V. WORKAROUND

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

VI. VENDOR RESPONSE

Kaspersky Lab reports that it has fixed this vulnerability as of January
2nd, 2007. In addition, they stated the following.

"There is no need to download any special patches. All installed Kaspersky
Lab products are updated automatically through the regular signature-update
functionality. There is not need to contact Kaspersky Lab to obtain this
fix."

VII. CVE INFORMATION

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

VIII. DISCLOSURE TIMELINE

12/12/2006  Initial vendor notification
12/12/2006  Initial vendor response
01/05/2007  Coordinated public disclosure

IX. CREDIT

The discoverer of this vulnerability wishes to remain anonymous.

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X. LEGAL NOTICES

Copyright © 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 of
the information constitutes acceptance for use in an AS IS condition.
There are no warranties with regard to this information. Neither the
author nor the publisher accepts any liability for any direct, indirect,
or consequential loss or damage arising from use of, or reliance on, this
information.