Vulnerability Note VU#446012

Microsoft Word object pointer memory corruption vulnerability

Overview

A memory corruption vulnerability in Microsoft Word could allow a remote attacker to execute arbitrary code with the privileges of the user running Word.

I. Description

Microsoft Word contains a memory corruption vulnerability. According to Microsoft Security Bulletin MS06-027:

When a user opens a specially crafted Word document using a malformed object pointer, it may corrupt system memory in such a way that an attacker could execute arbitrary code.

Office documents can contain embedded objects. For example, a malicious Word document could be embedded in an Excel or PowerPoint document. Office documents other than Word documents could be used as attack vectors.

For more information, including a complete list of affected software refer to Microsoft Security Bulletin MS06-027

Note that working exploit code is available for this vulnerability.

II. Impact

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.

III. Solution

Apply a patch from Microsoft

Microsoft addresses this vulnerability with the updates listed in Microsoft Security Bulletin MS06-027.

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 for more information.

Consult Microsoft Security Bulletin MS06-027 and Microsoft Security Advisory (919637)

Microsoft Security Bulletin MS06-027 and Microsoft Security Advisory (919637) list workarounds to reduce the chances of exploitation, including

Run Word in Safe Mode (winword.exe /safe)
Do not use Word as the email editor in Outlook

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, .dot, .rtf) may not detect all Word documents.

Systems Affected

Vendor	Status	Date Notified	Date Updated
Microsoft Corporation	Vulnerable	13-Jun-2006

References

http://www.us-cert.gov/cas/techalerts/TA06-139A.html
http://www.us-cert.gov/cas/alerts/SA06-139A.html
http://www.microsoft.com/technet/security/Bulletin/MS06-027.mspx
http://isc.sans.org/diary.php?storyid=1345
http://isc.sans.org/diary.php?storyid=1346
http://blogs.technet.com/msrc/archive/2006/05/19/429353.aspx
http://www.microsoft.com/technet/security/advisory/919637.mspx
http://office.microsoft.com/en-us/assistance/HP030823931033.aspx
http://www.microsoft.com/downloads/details.aspx?familyid=95E24C87-8732-48D5-8689-AB826E7B8FDF&displaylang=en
http://blogs.technet.com/msrc/archive/2006/05/20/429612.aspx
http://www.secunia.com/advisories/20153
http://www.securityfocus.com/bid/18037
http://xforce.iss.net/xforce/xfdb/26556
http://www.securitytracker.com/alerts/2006/May/1016130.html
http://www.osvdb.org/displayvuln.php?osvdb_id=25635

Credit

Information used in this document came from the SANS Internet Storm Center and Microsoft.

This document was written by Art Manion.

Other Information

Date Public:	2006-05-19
Date First Published:	2006-05-19
Date Last Updated:	2006-06-14
CERT Advisory:
CVE-ID(s):	CVE-2006-2492
NVD-ID(s):	CVE-2006-2492
US-CERT Technical Alerts:
Metric:	41.85
Document Revision:	34

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Produced 2006 by US-CERT, a government organization
Disclaimers and copyright information

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