Microsoft Fixes NT 4.0 Bug
- By Scott Bekker
- January 13, 2000
Microsoft released a patch to eliminate a security vulnerability in Windows NT 4.0. The vulnerability could allow a user logged onto an NT 4.0 machine from the keyboard to become an administrator on the machine.
LPC Ports is a facility that allows LPC calls on a machine. One of the functions in the LPC Ports API set enables, by design, a server thread to impersonate a client thread on the same machine. A flaw in the validation portion of the function would allow a malicious user to create both the server and client threads and manipulate the impersonation request to allow it to run in the context of any desired user on the local machine, including the System itself.
The primary risk is that a malicious user could gain additional privileges on the local machine. However, it could also be used to cause audit logs to indicate that certain actions were taken by another user.
All flavors of Windows NT 4.0 are affected by the vulnerability. The patch for Windows NT 4.0 Workstation, Windows NT 4.0 Server, and Windows NT 4.0 Server, Enterprise Edition are available for Intel platform machines at http://www.microsoft.com/downloads/release.asp?ReleaseID=17382 and for Alpha machines at http://www.microsoft.com/downloads/release.asp?ReleaseID=17383. A patch for Windows NT 4.0 Server, Terminal Server Edition will be available soon. -- Isaac Slepner
Scott Bekker is editor in chief of Redmond Channel Partner magazine.