// back

Microsoft Office WPG Image File Heap Buffer Overflow Vulnerability

08.12.08

BACKGROUND

Microsoft Office contains a number of input filters. These input filters allow transparent conversion from external types into a form that the Office applications can use. More information on import filters in Microsoft Office 2002 is available at the following URL.

http://support.microsoft.com/?scid=kb;en-us;290362

DESCRIPTION

Remote exploitation of a buffer overflow vulnerability in Microsoft Corp.'s Office filter for WordPerfect Graphics Files, could allow an attacker to execute arbitrary code with the privileges of the victim.

This vulnerability specifically lies within the "WPGIMP32.FLT" module. A heap overflow can occur when processing a malformed Wordperfect Graphics (WPG) file. By corrupting heap memory, it is possible to execute arbitrary code.

ANALYSIS

Exploitation allows an attacker to execute arbitrary code in the context of the targeted user. In order to exploit this issue, a targeted user must process an attacker supplied WPG file with Microsoft Office. This issue could be exploited by using a malformed WPG file, or by using a Wordperfect document containing such a file.

By default, Microsoft Office Products do not register the WPG or WP file types and the system will prompt the user for the application to open the files with. Additionally the Microsoft Web Service does not offer suggestions as to which application to use to open these extensions.

The Word Perfect Importer is not installed by default and may require an installation CD in order to install this feature. Users will likely be shown a dialog asking if they wish to install this Importer upon opening a Word Perfect document file type.

DETECTION

iDefense has confirmed this vulnerability in the following versions of Microsoft Office; Office XP SP3, Office 2003 SP2, Office 97. Other versions may also be affected.

WORKAROUND

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

VENDOR RESPONSE

Microsoft has officially addressed this vulnerability with Security Bulletin MS08-044. For more information, consult their bulletin at the following URL.

http://www.microsoft.com/technet/security/bulletin/ms08-044.mspx

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-3460 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org/), which standardizes names for security problems.

DISCLOSURE TIMELINE

11/07/2006 Initial vendor notification
11/07/2006 Initial vendor response
08/12/2008 Coordinated public disclosure

CREDIT

This vulnerability was reported to iDefense by Damian Put.

Get paid for vulnerability research
http://labs.idefense.com/methodology/vulnerability/vcp.php

Free tools, research and upcoming events
http://labs.idefense.com/

LEGAL NOTICES

Copyright © 2008 Verisign, Inc.

Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customer service for permission.

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.