Vulnerability Note VU#167928

Microsoft Word malformed string vulnerability

Original Release date: 06 Dec 2006 | Last revised: 23 Feb 2007


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


Microsoft Word contains a vulnerability that could be exploited when Word opens a specially crafted document. It is possible that the vulnerability can be exploited by opening a Microsoft Office document that includes an embedded Word document.

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

Note that reports claim this vulnerability is actively being exploited.


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.

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Microsoft CorporationAffected-15 Feb 2007
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was reported by Microsoft.

This document was written by Jeff Gennari.

Other Information

  • CVE IDs: CVE-2006-5994
  • Date Public: 05 Dec 2006
  • Date First Published: 06 Dec 2006
  • Date Last Updated: 23 Feb 2007
  • Severity Metric: 37.87
  • Document Revision: 9


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