Public Vulnerability Reports

Microsoft Excel DVAL Heap Corruption Vulnerability

03.11.08

BACKGROUND

Microsoft Excel is the spreadsheet application that is included with Microsoft Corp's Office productivity software suite. More information is available at the following website.

http://office.microsoft.com/excel/

DESCRIPTION

Remote exploitation of a heap corruption vulnerability in Microsoft Corp.'s Excel spreadsheet application allows attackers to execute arbitrary code in the context of the user who started Excel.

The vulnerability exists in the handling of DVAL records in BIFF8 format spreadsheet files. When certain fields are set to invalid values, heap corruption occurs.

ANALYSIS

Exploitation allows attackers to execute arbitrary code in the context of the user who started Excel. Exploitation requires that attackers persuade users to open a maliciously crafted file in Excel.

DETECTION

iDefense has confirmed the existence of this vulnerability in Microsoft Excel 2003 and Excel 2007. Previous versions may also be affected.

WORKAROUND

Disabling support for legacy binary file formats in the registry will prevent exploitation of this issue. However, this workaround is not available for all versions of Microsoft Excel.

VENDOR RESPONSE

Microsoft has officially addressed this vulnerability with Security Bulletin MS08-014. Previous releases, specifically Office 2007 SP1 and Office 2003 SP3, included a fix for this issue. For more information, consult their bulletin at the following URL.

http://www.microsoft.com/technet/security/Bulletin/ms08-014.mspx

CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2008-0111 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

05/09/2007 Initial vendor notification
05/09/2007 Initial vendor response
03/11/2008 Coordinated public disclosure

CREDIT

This vulnerability was discovered by Greg MacManus, iDefense Labs.

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.