Published:
06 November 2000
Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2000.332 -- Microsoft Security Bulletin (MS00-086) Patch Available for "Web Server File Request Parsing" Vulnerability 7 November 2000 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Internet Information Services 5.0 Vendor: Microsoft Impact: Execute Arbitrary Code/Commands Access Required: Remote Ref: ESB-2000.295 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Microsoft Security Bulletin (MS00-086) - - -------------------------------------- Patch Available for "Web Server File Request Parsing" Vulnerability Originally posted: November 06, 2000 Summary ======= Microsoft has released a patch that eliminates a serious security vulnerability in Microsoft(r) Internet Information Services 5.0. The vulnerability could enable a malicious user to run operating system commands on an affected web server. Microsoft strongly urges all customers using IIS 5.0 to apply the patch immediately. IIS 4.0 is not affected by the vulnerability. Frequently asked questions regarding this vulnerability and the patch can be found at http://www.microsoft.com/technet/security/bulletin/fq00-086.asp Issue ===== When IIS receives a valid request for an executable file, it passes the name of the requested file to the underlying operating system for processing. However, due to an implementation flaw in IIS 5.0, it is possible to create a specially-malformed file request that contains both a file name and one or more operating system commands. Upon receiving such a request, IIS 5.0 would pass the entire string to the operating system, which would first process the file and then execute the commands. The file would need to reside in a folder to which the user had execute permissions, but it would not necessarily need to be an executable file. The ability to execute operating system commands on the web server would enable a malicious user to take virtually any action that an interactively-logged on user could take. Although this would not give the malicious user administrative control over the server, it would nevertheless enable him to cause widespread damage. He could, for instance, add, delete or change files on the server, run code that was already on the server, or upload code of his choice and run it. Microsoft strongly recommends that all customers running IIS 5.0 immediately apply the patch for this vulnerability. The patch also eliminates the "Web Server Directory Traversal" vulnerability discussed in Microsoft Security Bulletin MS00-078. IIS 4.0 is not affected by the vulnerability, and IIS 4.0 customers do not need to take any action. Affected Software Versions ========================== - Microsoft Internet Information Service 5.0 Note: IIS 4.0 is not affected by the vulnerability. Patch Availability ================== - English: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25547 - Simplified Chinese: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25580 - Traditional Chinese: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25581 - German: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25582 - Japanese: http://www.microsoft.com/Downloads/Release.asp?ReleaseID=25583 Note: This patch can be applied atop system running either Windows 2000 Gold or Service Pack 1. It will be included in Windows 2000 Service Pack 2. Note: Additional security patches are available at the Microsoft Download Center More Information ================ Please see the following references for more information related to this issue. - Frequently Asked Questions: Microsoft Security Bulletin MS00-086, http://www.microsoft.com/technet/security/bulletin/fq00-086.asp - Microsoft Knowledge Base article Q277873 discusses this issue and will be available soon. - Microsoft TechNet Security web site, http://www.microsoft.com/technet/security/default.asp Obtaining Support on this Issue =============================== This is a fully supported patch. Information on contacting Microsoft Product Support Services is available at http://support.microsoft.com/support/contact/default.asp. Acknowledgments =============== Microsoft thanks NSFocus (http://www.nsfocus.com) for reporting this issue to us and working with us to protect customers. Revisions ========= - November 06, 2000: Bulletin Created. - - -------------------------------------------------------------- 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. Last Updated November 06, 2000 - -----BEGIN PGP SIGNATURE----- Version: PGP Personal Privacy 6.5.3 iQEVAwUBOgcFAY0ZSRQxA/UrAQEN2wf+Ol4R3fCxzHhOnq5FUt88FrQSY/4E7Y1Y Odf5fjNJja4Pt322teFSo3wWzmbmsfFgrJtD8Dk92O4FzIdj9TqQGrWEO1ixPPAr 3FLk+EqtaNTp9rA958OWDtdJr/9kS+uCtPWz9Yvy3Vb6pMcUJWpHF54HTxoQ3fb0 LpT1r6SlYo6Om1Ptu1qNACb2mAv4/KcJtXyj4zxne4zI1+lKJYdBQXvWFqnTNxm5 GTjwBrE8H83W3f/kFUhsZHVz1TAgNuklXuprLMsueS9Gsk4JLSQq7KEMuvY4I6VM PQ+oiti4pz6lOSEnRe20NW5hIbuHJkoETd7xa7Ybv/c2qeZuuS9Auw== =N/wR - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the original authors to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBOlSNLih9+71yA2DNAQHgowP/XBzGVU6IOAXSFuC8+2WLUzhUdcm/7Kns NX99eBMAeX1HHgc6vMwD1oacV9o1DQuwstMvlB870CpAdBj0lL+BO0adWUXGPhzG tOPbCXCCZaRe6appvkRkLHcbIT2R1xhluSXIl3wDoePms5ySE++/aAcFK8VDrqGK lyZAjf6ExZU= =33M7 -----END PGP SIGNATURE-----