__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft Flaw in ISAPI Extension for Windows Media Services Could Cause Code Execution [Microsoft Security Bulletin MS03-022] June 25, 2003 20:00 GMT Number N-109 ______________________________________________________________________________ PROBLEM: There is a flaw in the way nsiislog.dll processes incoming client requests. SOFTWARE: Microsoft Windows 2000 DAMAGE: An attacker could send specially formed HTTP request to the server that could cause IIS to fail or execute code on the user's system. SOLUTION: Apply patch as stated in Microsoft's security bulletin. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. An attacker attempting to exploit this ASSESSMENT: vulnerability would have to be aware which computers on the network had Windows Media Services installed on it and send a specific request to that server. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/n-109.shtml ORIGINAL BULLETIN: http://www.microsoft.com/technet/treeview/ default.asp?url=/technet/security/bulletin/MS03-022.asp ______________________________________________________________________________ [***** Start Microsoft Security Bulletin MS03-022 *****] Microsoft Security Bulletin MS03-022 Flaw in ISAPI Extension for Windows Media Services Could Cause Code Execution (822343) Originally posted: June 25, 2003 Summary Who should read this bulletin: System administrators running Microsoft® Windows® 2000 Impact of vulnerability: Allow an attacker to execute code of their choice Maximum Severity Rating: Important Recommendation: System administrators should install the patch at the earliest available opportunity. End User Bulletin: An end user version of this bulletin is available at: http://www.microsoft.com/security/security_bulletins/ms03-022.asp. Affected Software: * Microsoft Windows 2000 Not Affected Software Versions: * Windows NT 4.0 * Microsoft Windows XP * Microsoft Windows Server 2003 Technical details Technical description: Microsoft Windows Media Services is a feature of Microsoft Windows 2000 Server, Advanced Server, and Datacenter Server and is also available in a downloadable version for Windows NT 4.0 Server. Windows Media Services contains support for a method of delivering media content to clients across a network known as multicast streaming. In multicast streaming, the server has no connection to or knowledge of the clients that may be receiving the stream of media content coming from the server. To facilitate logging of client information for the server, Windows 2000 includes a capability specifically designed to enable logging for multicast transmissions. This logging capability is implemented as an Internet Services Application Programming Interface (ISAPI) extension – nsiislog.dll. When Windows Media Services are added through add/remove programs to Windows 2000, nsiislog.dll is installed in the Internet Information Services (IIS) Scripts directory on the server. Once Windows Media Services is installed, nsiislog.dll is automatically loaded and used by IIS. There is a flaw in the way nsiislog.dll processes incoming client requests. A vulnerability exists because an attacker could send specially formed HTTP request (communications) to the server that could cause IIS to fail or execute code on the user's system. Windows Media Services is not installed by default on Windows 2000. An attacker attempting to exploit this vulnerability would have to be aware which computers on the network had Windows Media Services installed on it and send a specific request to that server. Mitigating factors: * Windows Media Services 4.1 is not installed by default on Windows 2000. * Windows Media Services are not available for Windows 2000 Professional. Severity Rating: Windows 2000 Important The above assessment is based on the types of systems affected by the vulnerability, their typical deployment patterns, and the effect that exploiting the vulnerability would have on them. Vulnerability identifier: CAN-2003-0349 Tested Versions: Microsoft tested Windows NT 4.0, Windows 2000, Windows XP and Windows Server 2003 to assess whether they are affected by these vulnerabilities. Previous versions are no longer supported, and may or may not be affected by these vulnerabilities. Patch availability Download locations for this patch * Microsoft Windows 2000: http://microsoft.com/downloads/ details.aspx?FamilyId=F772E131-BBC9-4B34-9E78-F71D9742FED8&displaylang=en Additional information about this patch Installation platforms: This patch can be installed on systems running Microsoft Windows 2000 Service Pack 2, Windows 2000 Service Pack 3 and Microsoft Windows 2000 Service Pack 4. Inclusion in future service packs: The fix for this issue will be included in Windows 2000 Service Pack 5. Reboot needed: No. Patch can be uninstalled: No. Superseded patches: This patch supercedes the patch provided with MS03-019. Verifying patch installation: * To verify that the patch has been installed on the machine, confirm that the following registry key has been created on the machine: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Windows Media Services\wm822343 * To verify the individual files, use the date/time and version information provided in Knowledge Base article 822343. Caveats: None Localization: Localized versions of this patch are available at the locations discussed in “Patch Availability”. Obtaining other security patches: Patches for other security issues are available from the following locations: * Security patches are available from the Microsoft Download Center, and can be most easily found by doing a keyword search for "security_patch". * Patches for consumer platforms are available from the WindowsUpdate web site Other information: Acknowledgments Microsoft thanks Brett Moore for reporting this issue to us and working with us to protect customers. Support: * Microsoft Knowledge Base article 822343 discusses this issue and will be available approximately 24 hours after the release of this bulletin. Knowledge Base articles can be found on the Microsoft Online Support web site. * Technical support is available from Microsoft Product Support Services. There is no charge for support calls associated with security patches. Security Resources: The Microsoft TechNet Security Web Site provides additional information about security in Microsoft products. Disclaimer: 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. Revisions: * V1.0 (June 25, 2003): Bulletin Created. [***** End Microsoft Security Bulletin MS03-022 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Microsoft Corporation for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. 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