By default, several of the processes running in the interactive desktop do so with LocalSystem privileges. As a result, an attacker who had the ability to log onto a system interactively could potentially run a program that would levy a WM_TIMER request upon such a process, causing it to take any action the attacker specified. This would give the attacker complete control over the system. In addition to addressing this vulnerability, the patch also makes changes to several processes that run on the interactive desktop with high privileges.
Microsoft Windows NT 4.0
Microsoft Windows NT 4.0, Terminal Server Edition
Microsoft Windows 2000
Microsoft Windows XP
Windows NT 4.0, Terminal Server Edition: