Vulnerability Note VU#926676

Microsoft WordPad Text Converter vulnerable to remote code execution

Overview

The WordPad Text Converter for Word 97 files included in some versions of Windows contains an unspecified error which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

Microsoft WordPad is a text editor included by default with the Windows operating system. It includes WordPad Text Converters that allow users who do not have Microsoft Word installed to open documents in older file formats, including Microsoft Office Word 97.

An unspecified error in the way that the WordPad Text Converter for Word 97 handles files in this format results in memory corruption that could allow an attacker to execute arbitrary code. Microsoft Office Word 97 files may have file extensions such as .doc, .wri, or .rtf. While Microsoft Office Word has the ability to open Office Word 97 files, it is not affected by this vulnerability. However, in the default configuration, Windows will open files having the .wri extension with WordPad. Therefore, it is likely that systems that have Microsoft Office Word installed will still open a malicious Microsoft Office Word 97 document with this extension using the affected WordPad.

Microsoft notes that Windows XP Service Pack 3, Windows Vista and Windows Vista Service Pack 1 (including x64 editions), and Windows Server 2008 are not affected by this vulnerability.

This vulnerability is currently being exploited in the wild.

II. Impact

By convincing a user to view a specially crafted Word 97 document (e.g., an attachment supplied in email), a remote attacker may be able to execute arbitrary commands with the privileges of the user.

III. Solution

We are currently unaware of a practical solution to this problem.

Disable the WordPad Text Converter for Word 97 file format

Microsoft has included instructions for disabling the affected component in Microsoft Security Advisory (960906).

Systems Affected

Vendor	Status	Date Updated
Microsoft Corporation	Vulnerable		2008-12-11

References

http://www.microsoft.com/technet/security/advisory/960906.mspx

Credit

This document was written by Chad R Dougherty.

Other Information

Date Public	12/09/2008
Date First Published	12/11/2008 09:14:29 AM
Date Last Updated	12/11/2008
CERT Advisory
CVE Name	CVE-2008-4841
Metric	6.88
Document Revision	11

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