Vulnerability Note VU#740636

Overview

The Microsoft Windows Client/Server Run-time Subsystem (CSRSS) process fails to properly handle error messages. This vulnerability may allow a remote attacker to execute arbitrary code.

Description

According to Microsoft Security Bulletin MS07-021: CSRSS is the user-mode portion of the Win32 subsystem. CSRSS stands for client/server run-time subsystem and is an essential subsystem that must be running at all times. CSRSS is responsible for console windows, creating and/or deleting threads. The CSRSS process fails to properly handle error messages possibly allowing a double free vulnerability to occur. More information is available in Microsoft Security Bulletin MS07-021. Note that proof-of-concept code is available for this vulnerability.

Impact

A remote attacker may be able to execute arbitrary code on a vulnerable system.

Solution

Apply update from Microsoft Microsoft has released an update for this vulnerability in Microsoft Security Bulletin MS07-021.

Systems Affected (Learn More)

Vendor	Status	Date Notified	Date Updated
Microsoft Corporation	Affected	-	10 Apr 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

References

• http://www.microsoft.com/technet/security/bulletin/ms07-021.mspx
• http://www.determina.com/security.research/vulnerabilities/csrss-harderror.html
• http://www.kuban.ru/forum_new/forum2/files/19124.html
• http://bugtraq.ru/cgi-bin/forum.mcgi?type=sb&b=21&m=140672
• http://www.microsoft.com/technet/security/bulletin/ms07-021.mspx

Credit

This vulnerability was reported by Tim Garnett of Determina Security Research .

This document was written by Jeff Gennari.

Other Information

• CVE IDs: CVE-2006-6797
• Date Public: 15 Dec 2006
• Date First Published: 11 Apr 2007
• Date Last Updated: 11 Apr 2007
• Severity Metric: 7.44
• Document Revision: 12