DOCUMENT:Q260838 16-MAY-2002 [iis] TITLE :MS00-031: IIS Stops Servicing HTR Requests PRODUCT :Internet Information Server PROD/VER::4.0,5.0 OPER/SYS: KEYWORDS:kbSecurity kbWin2000PreSP1Fix kbWinNT400PreSP7Fix kbWin2000sp1Fix kbgraphxlinkcritical ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Internet Information Server version 4.0 - Microsoft Internet Information Services version 5.0 ------------------------------------------------------------------------------- SYMPTOMS ======== If a malicious user provides a password change request that is missing an expected delimiter, the algorithm conducts an unbounded search. This prevents the servicing of additional HTR requests, and can also slow the overall response of the server. CAUSE ===== The body of the request for a HTR page is assumed to be valid. RESOLUTION ========== Windows 2000 ------------ The original release of this fix is available in Windows 2000 Service Pack 1. For additional information on Windows 2000 Service Pack 1, click the article number below to view the article in the Microsoft Knowledge Base: Q260910 How to Obtain the Latest Windows 2000 Service Pack For additional information about what the updated package fixes, click the article numbers below to view the articles in the Microsoft Knowledge Base: Q267560 Changing the URL in a Specific Manner May Expose Contents of a File Q267559 GET on .Htr File Can Cause a "Denial of Service" or Enable Directory Browsing Q260069 Malformed HTR Request Returns Source Code for ASP Scripting Files A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 that contains this fix. To resolve this problem immediately, download the fix as instructed below or contact Microsoft Product Support Services to obtain the fix. 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 NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The following file is available for download from the Microsoft Download Center: DownloadDownload Q267559_w2k_sp2_x86_en.exe now (http://www.microsoft.com/Downloads/Release.asp?ReleaseID=22708) For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base: Q119591 How to Obtain Microsoft Support Files from Online Services Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. After it is posted, the file is housed on secure servers that prevent any unauthorized changes to the file. The English version of this fix should have the following file attributes or later: Date Time Version Size File name ----------------------------------------------------- 07/07/2000 03:17p 5.00.2195.2100 46,352 Ism.dll Windows NT 4.0 -------------- A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows NT 4.0 that contains this fix. To resolve this problem immediately, download the fix as instructed below or contact Microsoft Product Support Services to obtain the fix. 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 NOTE: In special cases, charges that are normally incurred for support calls may be canceled, if a Microsoft Support Professional determines that a specific update will resolve your problem. Normal support costs will apply to additional support questions and issues that do not qualify for the specific update in question. The following file is available for download from the Microsoft Download Center: US English: x86: DownloadDownload Ismpst4i.exe now (http://www.microsoft.com/Downloads/Release.asp?ReleaseID=20905) Alpha: DownloadDownload Ismpst4a.exe now (http://www.microsoft.com/Downloads/Release.asp?ReleaseID=20905) Chinese (Simplified): x86: DownloadDownload Ismpst4i.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/CN/Ismpst4i.exe) x86 Symbols: DownloadDownload Ismpst4is.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/CN/Ismpst4is.exe) Alpha: DownloadDownload Ismpst4a.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/CN/Ismpst4a.exe) Alpha Symbols: DownloadDownload Ismpst4as.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/CN/Ismpst4as.exe) Chinese (Traditional): x86: DownloadDownload Ismpst4i.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/TW/Ismpst4i.exe) x86 Symbols: DownloadDownload Ismpst4is.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/TW/Ismpst4is.exe) Alpha: DownloadDownload Ismpst4a.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/TW/Ismpst4a.exe) Alpha Symbols: DownloadDownload Ismpst4as.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/TW/Ismpst4as.exe) German: x86: DownloadDownload Ismpst4i.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/DE/Ismpst4i.exe) x86 Symbols: DownloadDownload Ismpst4is.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/DE/Ismpst4is.exe) Alpha: DownloadDownload Ismpst4a.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/DE/Ismpst4a.exe) Alpha Symbols: DownloadDownload Ismpst4as.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/DE/Ismpst4as.exe) Japanese: x86: DownloadDownload Ismpst4i.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/JA/Ismpst4i.exe) x86 Symbols: DownloadDownload Ismpst4is.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/JA/Ismpst4is.exe) Alpha: DownloadDownload Ismpst4a.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/JA/Ismpst4a.exe) Alpha Symbols: DownloadDownload Ismpst4as.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/JA/Ismpst4as.exe) Korean: x86: DownloadDownload Ismpst4i.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/KO/Ismpst4i.exe) x86 Symbols: DownloadDownload Ismpst4is.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/KO/Ismpst4is.exe) Alpha: DownloadDownload Ismpst4a.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/KO/Ismpst4a.exe) Alpha Symbols: DownloadDownload Ismpst4as.exe now (http://download.microsoft.com/download/iis40/Patch/Q260838/NT4ALPHA/KO/Ismpst4as.exe) Microsoft Windows NT Server version 4.0, Terminal Server Edition ---------------------------------------------------------------- To resolve this problem, obtain the Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package (SRP). For additional information about the SRP, click the article number below to view the article in the Microsoft Knowledge Base: Q317636 Windows NT Server 4.0, Terminal Server Edition, Security Rollup Package STATUS ====== Windows 2000 ------------ Microsoft has confirmed this problem could result in some degree of security vulnerability in Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 1. Windows NT 4.0 -------------- Microsoft has confirmed this problem could result in some degree of security vulnerability in Internet Information Server 4.0. MORE INFORMATION ================ For related information about this problem, please visit the following Microsoft Web site: http://www.microsoft.com/technet/security/bulletin/ms00-031.asp For additional security-related information about Microsoft products, please visit the following Microsoft Web site: http://www.microsoft.com/security/ For additional information about what else is fixed by this update, click the article number below to view the article in the Microsoft Knowledge Base: Q260069 Malformed HTR Request Returns Source Code for ASP Scripting Files Additional query words: security_patch DoS denial of service ====================================================================== Keywords : kbSecurity kbWin2000PreSP1Fix kbWinNT400PreSP7Fix kbWin2000sp1Fix kbgraphxlinkcritical Technology : kbiisSearch kbiis500 kbiis400 Version : :4.0,5.0 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.