DOCUMENT:Q298340 15-AUG-2002 [iis] TITLE :MS01-044: Patch Available for WebDAV Denial of Service PRODUCT :Internet Information Server PROD/VER::5.0 OPER/SYS: KEYWORDS:kbSecurity kbWin2000PreSP3Fix KbSECVulnerability KbSECBulletin KbSECHack kbWin2000sp3fi ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Internet Information Services version 5.0 ------------------------------------------------------------------------------- SYMPTOMS ======== In Internet Information Services (IIS) 5.0, a denial of service vulnerability exists that an attacker could exploit to temporarily disrupt Web services on an IIS 5.0 server. Mitigating Factors: - The effect of an attack would be temporary. The server would automatically resume normal service as soon as the malformed requests stopped arriving. - This vulnerability does not provide an attacker with any capability to carry out WebDAV requests. - This vulnerability does not provide any capability to compromise data on the server or gain administrative control over it. - This vulnerability only affects IIS 5.0. CAUSE ===== This vulnerability occurs because of the way that WebDAV handles a particular type of very long, invalid request. The net effect is to cause an access violation that results in the failure of the IIS 5.0 process. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: Q260910 How to Obtain the Latest Windows 2000 Service Pack The English version of this fix should have the following file attributes or later: Date Time Version Size File name ------------------------------------------------------ 12-May-2001 1815 5.0.2195.3608 246,032 Httpext.dll STATUS ====== Microsoft has confirmed that this problem may cause a degree of security vulnerability in Internet Information Services 5.0. This problem was first corrected in Windows 2000 Service Pack 3. MORE INFORMATION ================ This patch also contains fixes for the problems described in the following Microsoft Knowledge Base article: Q297860 IIS 5.0 Security and Post-Windows NT 4.0 SP5 IIS 4.0 Patch Rollup For more information on this vulnerability, see the following Microsoft Web site: http://www.microsoft.com/technet/security/bulletin/ms01-044.asp For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base: Q265173 The Datacenter Program and Windows 2000 Datacenter Server Product For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base: Q296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot Additional query words: security_patch kbWin2000srp1 ====================================================================== Keywords : kbSecurity kbWin2000PreSP3Fix KbSECVulnerability KbSECBulletin KbSECHack kbWin2000sp3fix Technology : kbiisSearch kbiis500 Version : :5.0 Hardware : 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.