Critical Bug in Windows Workstation Service

Microsoft Security Bulletin MS03-049 announces a new Buffer Overrun in the Workstation Service affecting Windows 2000 and Windows XP. Blocking access to UDP ports 138, 139, 445 and TCP ports 138, 139, 445, or disabling the Workstation service can mitigate the bug. Microsoft notes that disabling the Workstation service will prevent access to shared file and print resources, so it should only be used on stand-alone systems. Installing the patches is, of course, the preferred method of dealing with the problem.