Summary:  On November 16 2005 Microsoft released Security Advisory 911052.  This advisory details a vulnerability in the Remote Procedure Call (RPC) process that could allow an attacker (via guest or other valid login credentials) to instigate a Denial of Service (DoS) event on certain Windows 2000 and XP machines. Microsoft (in addition to at least one well-known Internet security specialist organization) have reported that proof of concept code for an exploit of this vulnerability has been made available to the public; at the time of publication for this alert no active attacks utilizing this exploit have been reported.  Microsoft is currently listing the details of this advisory as "Under Investigation", meaning that a security bulletin (patch) and suggested workaround has not yet been released by the vendor.

Recommended Actions:  As a precautionary measure, Windows system managers and support personnel that maintain XP SP1 and Win2000 SP4 systems are encouraged to read the advisory (link provided below) and to revisit it periodically to determine if any patches/workarounds etc have been issued by the vendor.

ITS Actions:  ITS Systems Management and Operations Staff will apply all recommended workarounds/patches to the appropriate ITS servers as part of the next scheduled system update once they are made available from the vendor.

Resources:
Microsoft Security Advisory 911052:
http://www.microsoft.com/technet/security/advisory/911052.mspx

Microsoft Security Advisories main page:
http://www.microsoft.com/technet/security/advisory/default.mspx

Microsoft Security Bulletins main page:
http://www.microsoft.com/technet/security/current.aspx