DOCUMENT:Q162567 09-AUG-2001 [winnt] TITLE :Telnet to Port 135 Causes 100 Percent CPU Usage PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.51,4.0 OPER/SYS: KEYWORDS:kbnetworkkbbuglist kbfixlist ====================================================================== ------------------------------------------------------------------------------- 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 ------------------------------------------------------------------------------- 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 ====================================================================== 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 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.