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Microsoft Windows buffer overflow in Enhanced Metafile rendering API

Vulnerability Note VU#134756

Original Release Date: 2005-11-08 | Last Revised: 2005-11-09

Overview

Microsoft Windows Enhanced Metafile Format image rendering routines contain a buffer overflow flaw that may allow an attacker to cause a denial-of-service condition.

Description

Microsoft describes the Enhanced Metafile Format (EMF) as the following:

An EMF image is a 32-bit format that can contain both vector information and bitmap information. This format is an improvement over the Windows Metafile Format and contains extended features. For more information about image types and formats, see Microsoft Knowledge Base Article 320314. Additional information about these file formats is also available at the MSDN Library Web Site.

The Microsoft Windows EMF rendering routines may fail to properly check a buffer length, possibly resulting in a crash of the affected application or in the application failing to respond. Any program that uses these routines to render a specially-crafted image file is vulnerable to the issue.

Proof of concept code related to this issue is known to be available at this time.

Impact

A remote, unauthenticated attacker may cause an affected application to stop responding or crash.

Solution

Apply an update
Please see Microsoft Security Bulletin MS05-053 for details on updates, workarounds, and solutions.


Do not access EMF files from untrusted sources

Exploitation occurs by accessing a specially crafted EMF file (typically .emf). By only accessing EMF files from trusted or known sources, the chances of exploitation are reduced.

Attackers may host malicious EMF files on a website. In order to convince users to visit their sites, those attackers often use URL encoding, IP address variations, long URLs, intentional misspellings, and other techniques to create misleading links. Do not click on unsolicited links received in email, instant messages, web forums, or internet relay chat (IRC) channels. Type URLs directly into the browser to avoid these misleading links. While these are generally
good security practices, following these behaviors will not prevent exploitation of this vulnerability in all cases, particularly if a trusted site has been compromised or allows cross-site scripting.

Vendor Information

134756
 
Affected   Unknown   Unaffected

Microsoft Corporation

Updated:  November 08, 2005

Status

  Vulnerable

Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

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

Addendum

Please see Microsoft Security Bulletin MS05-053 for details on updates, workarounds, and solutions.

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


CVSS Metrics

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

References

Acknowledgements

Thanks to Microsoft and Hongzen Zhou for reporting this vulnerability.

This document was written by Ken MacInnis.

Other Information

CVE IDs: CVE-2005-0803
Severity Metric: 7.56
Date Public: 2005-03-18
Date First Published: 2005-11-08
Date Last Updated: 2005-11-09 21:30 UTC
Document Revision: 16

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