===================================================================== CERT-Renater Note d'Information No. 2006/VULN260 _____________________________________________________________________ DATE : 22/05/2006 HARDWARE PLATFORM(S) : / OPERATING SYSTEM(S) : Systems running Word 2003, Word XP (2002). ====================================================================== National Cyber Alert System Technical Cyber Security Alert TA06-139A Microsoft Word Vulnerability Original release date: May 19, 2006 Last revised: -- Source: US-CERT Systems Affected * Microsoft Word 2003 * Microsoft Word XP (2002) Microsoft Word is included in Microsoft Works Suite and Microsoft Office. Other versions of Word, and other Office programs may be affected or act as attack vectors. Overview A buffer overflow vulnerability in Microsoft Word could allow an attacker to execute arbitrary code on a vulnerable system. I. Description Microsoft Word contains a buffer overflow vulnerability. Opening a specially crafted Word document, including documents hosted on web sites or attached to email messages, could trigger the vulnerability. 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, please see Vulnerability Note VU#446012. II. Impact By convincing a user to open a specially crafted Word document, an attacker could execute arbitrary code on a vulnerable system. If the user has administrative privileges, the attacker could gain complete control of the system. III. Solution At the time of writing, there is no complete solution available. Consider the following workarounds: Do not open untrusted Word documents Do not open unfamiliar or unexpected Word or other Office documents, including those received as email attachments or hosted on a web site. Please see Cyber Security Tip ST04-010 for more information. Do not rely on file 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.d0c (note the digit "0") contains the correct file header information, Windows will open document.d0c with Word. Appendix A. References * Vulnerability Note VU#446012 - * Cyber Security Tip ST04-010 - ____________________________________________________________________ Information used in this document came from SANS and Microsoft. ____________________________________________________________________ The most recent version of this document can be found at: ____________________________________________________________________ Feedback can be directed to US-CERT Technical Staff. Please send email to with "TA06-139A Feedback VU#446012" in the subject. ____________________________________________________________________ For instructions on subscribing to or unsubscribing from this mailing list, visit . ____________________________________________________________________ Produced 2006 by US-CERT, a government organization. Terms of use: ____________________________________________________________________ Revision History May 19, 2006: Initial release ====================================================================== ========================================================= Les serveurs de référence du CERT-Renater http://www.urec.fr/securite http://www.cru.fr/securite http://www.renater.fr ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 151 bd de l'Hopital | fax : 01-53-94-20-41 + + 75013 Paris | email: certsvp@renater.fr + =========================================================