Microsoft has scheduled to release a security bulletin (out-of-band) to address a vulnerability in all currently supported versions of Windows.
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.
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.
Recommendation. Microsoft recommends that customers apply the update immediately.
This security update will be released outside of the usual monthly security bulletin release cycle in an effort to protect customers. Microsoft recommends customers prepare their systems and networks to apply this security bulletin immediately once released to help ensure that their computers are protected from attempted criminal attacks. The purpose of this notification is to assist customers with resource planning for this security bulletin release.
For more information about security updates, visit http://support.microsoft.com/default.aspx?scid=kb;EN-US;KB958644