Oct 2008: Microsoft Security Bulletin: MS08-067
Microsoft is breaking from their standard monthly release of Security Bulletins on the 2nd Tuesday of each month to release MS08-67. This Critical Security Bulletin addresses a vulnerability in the Server Service that could allow remote code execution by an attacker.
Here is how Microsoft describes the problem in the executive summary of the Security Bulletin:
This security update resolves a privately reported vulnerability in the Server service. The vulnerability could allow remote code execution if an affected system received a specially crafted RPC request. On Microsoft Windows 2000, Windows XP, and Windows Server 2003 systems, an attacker could exploit this vulnerability without authentication to run arbitrary code. It is possible that this vulnerability could be used in the crafting of a wormable exploit. Firewall best practices and standard default firewall configurations can help protect network resources from attacks that originate outside the enterprise perimeter.This security update is rated Critical for all supported editions of Microsoft Windows 2000, Windows XP, Windows Server 2003, and rated Important for all supported editions of Windows Vista and Windows Server 2008. For more information, see the subsection, Affected and Non-Affected Software, in this section.
The security update addresses the vulnerability by correcting the way that the Server service handles RPC requests. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability entry under the next section, Vulnerability Information.
This flaw affects all versions of Microsoft Windows. Part of the reason for the urgency of the concern, as stated in the Executive Summary above, is that on many versions of Windows the vulnerability can be exploited without interaction or authentication by the user, making it possible for an attacker to develop a worm based on this vulnerability.
Take a look at the Security Bulletin and follow the link to get the necessary patches to protect your system from exploits targeted at this vulnerability.
Microsoft Security Bulletin MS08-067
Vulnerability in Server Service Could Allow Remote Code Execution
Microsoft Criticality: Critical