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Q162567: Telnet to Port 135 Causes 100 Percent CPU Usage

Article: Q162567
Product(s): Microsoft Windows NT
Version(s): winnt:3.51,4.0
Operating System(s): 
Keyword(s): kbnetworkkbbuglist kbfixlist
Last Modified: 09-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Workstation versions 3.51, 4.0 
- Microsoft Windows NT Server versions 3.51, 4.0 
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SYMPTOMS
========

When a client uses the telnet utility to connect to port 135 of a computer
running Windows NT Server, and then types more than 10 random characters and
disconnects, the server CPU usage jumps to 100 percent and does not come back
down until the server is restarted.

CAUSE
=====

This problem is caused by a problem with the remote procedure call (RPC)
components in Windows NT.


RESOLUTION
==========

To resolve this problem, download and install the appropriate file:

Windows NT 3.51
---------------

This hotfix has been posted to the following Internet location:

  ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT351/hotfixes-postSP5/rpc-fix


Windows NT 4.0
--------------

This hotfix has been posted to the following Internet location:

  ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/hotfixes-postSP2/rpc-fix

STATUS
======

Microsoft has confirmed this problem could result in some degree of security
vulnerability in Windows NT version 4.0. This problem was corrected in the
latest Microsoft Windows NT 4.0 U.S. Service Pack. 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

Microsoft has confirmed this problem could result in some degree of security
vulnerability in Windows NT version 3.51. A fully supported fix is now
available, but it has not been fully regression tested and should only be
applied to systems determined to be at risk of attack. Please evaluate your
system's physical accessibility, network and Internet connectivity, and other
factors to determine the degree of risk to your system. If your system is
sufficiently at risk, Microsoft recommends you apply this fix. Otherwise, wait
for the next Windows NT service pack, which will contain this fix. Please
contact Microsoft Technical Support for more information.


Additional query words: Telnet RPC crash hang max prodnt

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Keywords          : kbnetwork kbbuglist kbfixlist
Technology        : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT400search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search
Version           : winnt:3.51,4.0
Issue type        : kbbug

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