iDefense Security Advisory 10.13.09
http://labs.idefense.com/intelligence/vulnerabilities/
Oct 13, 2009

I. BACKGROUND

The GDI+ library 'GdiPlus.dll' provides access to a number of graphics
methods, via a class based API. For more information on GDI+, please
visit following URL.

http://msdn2.microsoft.com/en-us/library/ms533798.aspx

Tagged Image File Format (TIFF) is a container format for storing
images. For more information about TIFF, please visit following URL.

http://partners.adobe.com/public/developer/tiff/index.html

II. DESCRIPTION

Remote exploitation of a heap based buffer overflow vulnerability in
Microsoft Corp.'s Windows GDI+ could allow an attacker to execute
arbitrary code with the privileges of the current user.

This vulnerability occurs when parsing a malformed TIFF file. By
supplying incorrect values in a BitsPerSample tag, it is possible to
trigger a heap based buffer overflow.

III. ANALYSIS

Successful exploitation allows an attacker to execute arbitrary code in
the context of the current user. Social engineering is required, as an
attacker must trick a user into viewing an image in the Web Browser,
viewing an e-mail with embedded image, opening an office file with
embbeded image, or downloading an image file and opening it within a
graphics rendering program.

IV. DETECTION

iDefense has confirmed the existence of this vulnerability in Windows XP
Service Pack 2. Please see the Microsoft bulletin for additional details
on affected software.

V. WORKAROUND

The following workarounds can be employed to mitigate exposure to this
vulnerability:

*Restrict access to gdiplus.dll
*Unregister vgx.dll

Instructions for employing/removing these workarounds can be found in
the bulletin.

VI. VENDOR RESPONSE

Microsoft has released a patch which addresses this issue. For more
information, consult their advisory at the following URL:

http://www.microsoft.com/technet/security/Bulletin/MS09-062.mspx

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2009-2502 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

12/18/2007  - Initial Contact
12/18/2007  - Initial Response
12/19/2007  - PoC Requested
12/19/2007  - PoC Sent
01/14/2008  - Status update received
03/27/2008  - Status update requested
03/28/2008  - Status update received - no estimated release date
04/28/2008  - Status update requested
04/28/2008  - Status update received - no estimated release date
01/11/2009  - Vendor states updates being silently released soon,
estimates "Summer" bulletin release
02/26/2009  - Vendor proposed tentative disclosure date of 08/11/2009
03/05/2009  - Status update requested
04/23/2009  - Vendor reset disclosure to 10/13/2009
10/13/2009  - Coordinated public disclosure.

IX. CREDIT

This vulnerability was reported to iDefense by wushi of team509.

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X. LEGAL NOTICES

Copyright © 2009 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,
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reliance on, this information.