Windows 7: Microsoft Security Bulletin MS10-025 - Critical.

Published: April 13, 2010 | Updated: April 27, 2010



Microsoft Security Bulletin MS10-025 - Critical

General Information
Executive Summary

This security update resolves a privately reported vulnerability in Windows Media Services running on Microsoft Windows 2000 Server. The vulnerability could allow remote code execution if an attacker sent a specially crafted transport information packet to a Microsoft Windows 2000 Server system running Windows Media Services. Firewall best practices and standard default firewall configurations can help protect networks from attacks that originate from outside the enterprise perimeter. Best practices recommend that systems that are connected to the Internet have a minimal number of ports exposed. On Microsoft Windows 2000 Server, Windows Media Services is an optional component and is not installed by default.

This security update is rated Critical for all supported editions of Microsoft Windows 2000 Server running Windows Media Services. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update was rereleased on April 27, 2010.

The rereleased security update addresses the vulnerability by modifying the way that the Windows Media Unicast Service (nsum.exe) handles transport info network packets. For more information about the vulnerability see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.

Recommendation. The majority of customers have automatic updating enabled and will not need to take any action because this security update will be downloaded and installed automatically. Customers who have not enabled automatic updating need to check for updates and install this update manually.

For information about specific configuration options in automatic updating, see Microsoft Knowledge Base Article 294871.
For administrators and enterprise installations, or end users who want to install this security update manually, Microsoft recommends that customers apply the update immediately using update management software, or by checking for updates using the Microsoft Update service.