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Microsoft Word malformed data structure vulnerability

Vulnerability Note VU#166700

Original Release Date: 2006-12-11 | Last Revised: 2007-02-23


A vulnerability in Microsoft Word could allow an attacker to execute arbitrary code on a vulnerable system.


Microsoft Word fails to properly handle malformed data structures allowing memory corruption to occur. This vulnerability can be triggered by opening a specially crafted document with Microsoft Word. It is possible that the vulnerability can be exploited by opening a Microsoft Office document that includes an embedded Word document.

We are aware of public reports of active exploitation of this vulnerability.

More information is available in Microsoft Security Bulletin MS07-014.


By convincing a user to open a specially crafted Word document, an attacker could execute arbitrary code with the privileges of the user running Word. If the user is logged in with administrative privileges, the attacker could take complete control of a vulnerable system.


Apply Update for Microsoft
Microsoft has addressed this vulnerability in Microsoft Security Bulletin MS07-014.

Do not open untrusted Word documents

Do not open unfamiliar or unexpected Word or other Office documents, particularly those hosted on web sites or delivered as email attachments. Please see Cyber Security Tip ST04-010.

Do not rely on file name extension filtering

In most cases, Windows will call Word to open a document even if the document has an unknown file extension. For example, if document.qwer contains the correct file header information, Windows will open document.qwer with Word. Filtering for common extensions (e.g., .doc, and .dot) will not detect all Word documents.

Disable automatic opening of Microsoft Office documents

By default, Microsoft Office 97 and Microsoft Office 2000 will configure Internet Explorer to automatically open Microsoft Office documents. This feature can be disabled by using the Office Document Open Confirmation Tool. Mozilla Firefox users should disable automatic opening of files, as specified in the Securing Your Web Browser document.

Vendor Information


Microsoft Corporation Affected

Updated:  February 13, 2007



Vendor Statement

We have not received a statement from the vendor.

Vendor Information

The vendor has not provided us with any further information regarding this vulnerability.


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If you have feedback, comments, or additional information about this vulnerability, please send us email.

CVSS Metrics

Group Score Vector



This issue was reported by Microsoft and McAfee.

This document was written by Jeff Gennari.

Other Information

CVE IDs: CVE-2006-6456
Severity Metric: 37.87
Date Public: 2006-12-10
Date First Published: 2006-12-11
Date Last Updated: 2007-02-23 13:24 UTC
Document Revision: 22

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