Security Administrator Tool causes high memory use in WUSER32 (178748)

SYMPTOMS

Computers running Windows NT Server may experience a low virtual memory condition. Closer examination of the Server Monitor reveals a high utilization of memory by Wuser32.exe (Systems Management Server Remote Control Agent) service. It will finally use up so much memory that no other process can allocate memory.

Left unchecked, this will render the server unable to respond to remote users' requests.

CAUSE

The Security Administrator Tool for Analyzing Networks (SATAN) is a UNIX- based testing and reporting tool that collects a variety of information about networked hosts. SATAN will attempt to access many UDP and TCP ports across the network in a very short space of time.

Wuser32.exe normally listens on UDP ports 1761 and 1762. When the SATAN utility scans these ports on a host running Wuser32, the service immediately starts to allocate memory at a rapid rate. As the memory utilization increases, the server is unable to allocate memory for other services running on the server (File, Print, SMS, WINS, and so forth). This continues until the server is unable to respond to any network requests. Normally, the interactive services are still active.

STATUS

Microsoft has confirmed this to be a problem in Systems Management Server version 1.2. This problem has been corrected in the latest U.S. service pack for Systems Management Server version 1.2. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

WORKAROUND

If you still want to perform SATAN scans on internal networks, you can disable scanning of UDP ports 1761, 1762, and TCP port 7161. This will enable the SATAN scans to be performed without triggering the problem.