Microsoft Windows NT 4.0 Patch: Winsock Mutex Vuln Update

This vulnerability exists because the mutex (a tool to prevent more than one process from accessing certain resources at the same time) that is used to control access to networking resources has inappropriately loose permissions. As a result, a malicious user with physical access to a Windows NT 4.0 computer could write a program to gain control of the mutex and deny access to all other users. By denying access to the mutex, the malicious users program could prevent any other programs from using the networking functions of the affected computer. This update corrects the inappropriate permissions of the affected mutex.

For more information about this vulnerability, please read Microsoft Security Bulletin MS01-003.