There is a flaw in the way the kernel passes error messages to a debugger. A vulnerability results because an attacker could write a program to exploit this flaw & run code of their choice. An attacker could exploit this vulnerability to take any action on the system including deleting data, adding accounts with administrative access, or reconfiguring the system.
Microsoft Windows NT 4.0
Microsoft Windows NT 4.0 Server, Terminal Server Edition
Microsoft Windows 2000
Microsoft Windows XP
Download locations for this patch