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Microsoft Excel Memory Corruption Vulnerability



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


Remote exploitation of a memory corruption vulnerability in Microsoft Corp.'s Excel could allow an attacker to execute arbitrary code with the privileges of the current user.

The vulnerability occurs when Excel parses a specially crafted Excel file. When parsing the Workbook record stream, a specific record type is not handled properly by the parsing code. This can result in a memory corruption vulnerability, which leads to the execution of arbitrary code.


Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user opening the file. To exploit this vulnerability, an attacker needs to convince a user to open a malicious file. Attackers typically accomplish this by e-mailing a targeted user the file or hosting the file on a Web page.


The following Microsoft products are vulnerable:

  • Excel 2002 Service Pack 3
  • Excel 2003 Service Pack 3
  • Excel 2007 Service Pack 2
  • Excel 2010 (32-bit editions)
  • Excel (64-bit editions)
  • Office 2004 for Mac
  • Office 2008 for Mac
  • Office for Mac 2011
  • Open XML File Format Converter for Mac
  • Excel Viewer Service Pack 2
  • Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats Service Pack 2


The vulnerability occurs in the core parsing code of Excel and this code can not be disabled; however, it is possible to disable the opening of the older binary format files and use MOICE to convert the file to the newer XML-based format. Customers can find these two methods in the Sources section of this report.


Microsoft Corp. has released patches which address this issue. Information about downloadable vendor updates can be found by clicking on the URLs shown.


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2011-1273 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


10/27/2010 Initial Vendor Notification
10/27/2010 Initial Vendor Reply
06/14/2011 Coordinated Public Disclosure


The discoverer of this vulnerability wishes to remain anonymous.

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Copyright © 2011 Verisign, Inc.

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