Public Vulnerability Reports

Microsoft Excel Long Palette Heap Overflow Vulnerability



Microsoft Excel is the spreadsheet application from the Microsoft Office System. More information is available at the following link:


Remote exploitation of an heap-based buffer overflow vulnerability in Microsoft Corp.'s Excel spreadsheet application format could allow an attacker to execute arbitrary code in the context of the user who started Excel.

The vulnerability specifically exists in the handling of the PALETTE record in BIFF8 format spreadsheet files. By supplying a record with too many entries, an exploitable buffer overflow condition can occur.


Successful exploitation of this vulnerability would allow an attacker to execute arbitrary code in the context of the user who opened the document. In order exploit this vulnerability, an attacker would need to convince the target to open an Excel spreadsheet file. Likely attack vectors include sending the file as an attachment in an email or linking to the file on a website.

Systems with a default install of Office 2000 will open Office documents, including Excel spreadsheet files, from websites without prompting the user. This allows an attacker to exploit this vulnerability without user interaction beyond visiting a website. Later versions of Office will not open these documents automatically unless the user has chosen this behavior.


iDefense Labs have confirmed the existence of this vulnerability in Microsoft Excel 2003 with all service packs and security updates. Previous versions of Excel are also likely to be affected.


Do not follow links or open files from unknown sources or that you were not expecting to receive.


Microsoft has addressed this vulnerability with Microsoft Security Bulletin MS07-002. A link to this bulletin can be found below.


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2007-0031 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


09/22/2006 Initial vendor notification
09/22/2006 Initial vendor response
01/09/2007 Coordinated public disclosure


This vulnerability was discovered by Greg MacManus, iDefense Labs.

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Copyright © 2006 Verisign, Inc.

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