DOCUMENT:Q238349 20-MAY-2002 [iis] TITLE :Specially-Malformed Header Creates Denial of Service PRODUCT :Internet Information Server PROD/VER:winnt:2.0,2.5,3.0,4.0 OPER/SYS: KEYWORDS:kbWinNT4sp6fix ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0, Terminal Server Edition - Microsoft Internet Information Server version 4.0 - Microsoft Site Server version 3.0 - Microsoft Commercial Internet System versions 2.0, 2.5 - Microsoft Site Server version 3.0, Commerce Edition ------------------------------------------------------------------------------- SYMPTOMS ======== A specially-malformed header in a GET request can create a Denial of Service in the W3 server and use all available memory on the Web server, causing Internet Information Server (IIS) to stop responding to any request. RESOLUTION ========== Windows NT Server or Workstation 4.0 and Internet Information Server -------------------------------------------------------------------- To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to: - http://www.microsoft.com/Windows/ServicePacks/ -or- - Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS Windows NT Server 4.0, Terminal Server Edition ---------------------------------------------- To resolve this problem, obtain the latest service pack for Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base: Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack STATUS ====== Microsoft has confirmed this to be a problem in Internet Information Server 4.0. This problem was first corrected in Windows NT Server version 4.0, Terminal Server Edition Service Pack 6.Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT Server 4.0 Service Pack 6 and Windows NT Server 4.0, Terminal Server Edition Service Pack 6. Additional query words: ====================================================================== Keywords : kbWinNT4sp6fix Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbNTTermServ400 kbNTTermServSearch kbSiteServSearch kbiisSearch kbAudDeveloper kbiis400 kbMCISSearch kbMCIS200 kbMCIS250 kbSiteServ300 kbSiteServ300Search Version : winnt:2.0,2.5,3.0,4.0 Hardware : ALPHA x86 Issue type : kbbug Solution Type : kbfix ============================================================================= 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 2002.