-----BEGIN PGP SIGNED MESSAGE----- __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft "Specialized Header" Vulnerability August 15, 2000 22:00 GMT Number K-065 _____________________________________________________________________________ PROBLEM: Microsoft has identified a vulnerability that under certain conditions may cause a web server to send source code of certain types of web files to a visiting user. PLATFORM: All platforms running Microsoft Internet Information Server (IIS) 5.0 DAMAGE: If a user creates a specialized header and appends one of several particular characters at the end of the request, IIS will locate the correct file but not recognize it as a file that needs to be processed by a scripting engine. Instead, it will simply send the file to the browser. SOLUTION: Install the patch indicated below. For Windows 2000 install Service Pack 1. _____________________________________________________________________________ VULNERABILITY The risk is LOW. If normal security recommendations regarding ASSESSMENT: .ASP files has been followed, there will be no sensitive information contained in the source code. _____________________________________________________________________________ [Start of Microsoft Security Bulletin] Microsoft Security Bulletin (MS00-058) - -------------------------------------- Patch Available for "Specialized Header" Vulnerability Originally posted: August 14, 2000 Summary ======= Microsoft has released a patch that eliminates a security vulnerability in Internet Information Server that ships with Microsoft(r) Windows 2000. Under certain conditions, the vulnerability could cause a web server to send the source code of certain types of web files to a visiting user. Frequently asked questions regarding this vulnerability and the patch can be found at http://www.microsoft.com/technet/security/bulletin/fq00-058.asp Issue ===== If an IIS server receives a file request that contains a specialized header as well as one of several particular characters at the end, the expected ISAPI extension processing may not occur. The result is that the source code of the file would be sent to the browser. It is important to note that normal security recommendations militate strongly against ever including sensitive information in .ASP files and, if these recommendations have been followed, there would be no sensitive information to compromise. The specialized header at issue here cannot be created via a standard Internet browser, so the request would need to be created by an alternate method. Affected Software Versions ========================== - Microsoft Internet Information Server 5.0 Patch Availability ================== - http://www.microsoft.com/Downloads/Release.asp?ReleaseID=23769 Note: This vulnerability is eliminated by installing Windows 2000 Service Pack 1 http://www.microsoft.com/windows2000/downloads/recommended/sp1/ We recommend that customers apply SP1 as the preferred option for eliminating this vulnerability, as it has been fully regression tested and includes fixes for additional issues. 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 MS00-058, http://www.microsoft.com/technet/security/bulletin/fq00-058.asp - Microsoft Knowledge Base article Q256888 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. Revisions ========= August 14, 2000: Bulletin Created. [End of Microsoft Security Bulletin] _____________________________________________________________________________ CIAC wishes to acknowledge the contributions of Microsoft 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 FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@llnl.gov For emergencies and off-hour assistance, DOE, DOE contractor sites, and the NIH may contact CIAC 24-hours a day. During off hours (5PM - 8AM PST), use one of the following methods to contact CIAC: 1. Call the CIAC voice number 925-422-8193 and leave a message, or 2. Call 888-449-8369 to send a Sky Page to the CIAC duty person or 3. Send e-mail to 4498369@skytel.com, or 4. Call 800-201-9288 for the CIAC Project Leader. Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ (or http://ciac.llnl.gov -- they're the same machine) Anonymous FTP: ftp.ciac.org (or ciac.llnl.gov -- they're the same machine) Modem access: +1 (925) 423-4753 (28.8K baud) +1 (925) 423-3331 (28.8K baud) 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. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) K-064: Linux Kernel Capability Vulnerability K-063: Netscape Java Vulnerability K-062: Vulnerabilities in Lotus Notes Domino Aired at DefCon 8 K-061: Microsoft Office HTML and IE Script Vulnerabilities K-060: Microsoft's Malformed E-Mail Header Vulnerability K-059: Microsoft DTS Password Vulnerability K-058: OpenSSH UseLogin Vulnerability K-057: Microsoft Active Setup Download Vulnerability K-056: IRIX WorkShop cvconnect(1M) Vulnerability K-055: HP Web JetAdmin Vulnerability -----BEGIN PGP SIGNATURE----- Version: 4.0 Business Edition iQCVAwUBOZnQXLnzJzdsy3QZAQGpVAQAj2B9e7gh+huQRP+yaBvCS78erftTf9IR ngIJwzN7uhAq4knnn/zGDLzDT7CTDPTibKj1CGQb4kGIyaiXltrJdRV5IEGHFdkh 0OivgAgDUQfZv48G6Li0kFQNUdFMck1cO4V3/+nPxKLW5ojLNMD9+/Ow4W4u3V61 3GVsxsthMME= =BDWN -----END PGP SIGNATURE-----