-----BEGIN PGP SIGNED MESSAGE----- __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft WebDAV Runs Scripts As User [Microsoft Bulletin MS01-022] April 20, 2001 00:00 GMT Number L-074 ______________________________________________________________________________ PROBLEM: The Microsoft WebDAV service does not differentiate between requests made by a user and those made by a script. A user browsing a web page containing a WebDAV script would unknowingly run that script with the user's privilages and possibly compromise the user's security. PLATFORM: Microsoft Data Access Component Internet Publishing Provider. WebDAV DAMAGE: The owner of a malicious web page could execute scripts on the user's behalf, giving the woner access to all of a user's web based resources. SOLUTION: Apply the patch as shown in Microsoft Security Bulletin MS01-022. http://www.microsoft.com/technet/security/bulletin/MS01-022.asp. ______________________________________________________________________________ VULNERABILITY The risk is LOW. The intruder would have to know all about the ASSESSMENT: user's accessible resources, including file names, network paths, etc. ______________________________________________________________________________ [***** Start Microsoft Security Bulletin *****] - - ----------------------------------------------------------------------- Title: WebDAV Service Provider Can Allow Scripts to Levy Requests as User Date: 18 April 2001 Software: Microsoft Data Access Component Internet Publishing Provider Impact: Web-based script could levy WebDAV requests on the user's behalf. Bulletin: MS01-022 Microsoft encourages customers to review the Security Bulletin at: http://www.microsoft.com/technet/security/bulletin/MS01-022.asp. - - ----------------------------------------------------------------------- Issue: ====== The Microsoft Data Access Component Internet Publishing Provider provides access to WebDAV resources over the Internet. By design, it should differentiate between requests made by a user and those made by a script running in the user's browser. However, because of an implementation flaw, it handles all requests in the security context of the user. As a result, if a user browsed to a web page or opened an HTML e-mail that contained script, that script could access web-based resources as the user. The specific actions an attacker could take via this vulnerability would depend on the Web-based resources available to the user, and the user's privileges on them. However, it is likely that at a minimum, the attacker could browse the user's intranet, and potentially access web-based e-mail as well. Mitigating Factors: ==================== - The attacker would need to possess significant inside information in order to carry out a successful attack, such as server names, folder structures, and other user- and network-specific information. This vulnerability would therefore be most likely used as part of an insider attack. - The vulnerability could not be exploited against stand-alone machines. - The vulnerability could not be exploited if Active Scripting was disabled in the Security Zone the script opened in. Patch Availability: =================== - A patch is available to fix this vulnerability. Please read the Security Bulletin http://www.microsoft.com/technet/security/bulletin/ms01-022.asp for information on obtaining this patch. - - ---------------------------------------------------------------------- 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. [***** End 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 (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/ (or http://ciac.llnl.gov -- they're the same machine) Anonymous FTP: ftp.ciac.org (or ciac.llnl.gov -- they're the same machine) 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) l-064: The Lion Internet Worm DDOS Risk L-065: Solaris Exploitation of snmpXdmid L-066: Internet Explorer MIME Mime Header Vulnerability L-067: Linux worm Adore L-068: Cisco VPN3000 Concentrator TELNET Vulnerability L-069: Cisco Content Services Switch User Account Vulnerability L-070: FTP Filename Expansion Vulnerability L-071: Various Vendors' Network Time Protocol (NTP) Vulnerability L-072: Cisco Catalyst 5000 Series 802.1x Vulnerability L-073: Microsoft ISA Web Proxy Service Denial of Service -----BEGIN PGP SIGNATURE----- Version: PGP for Business Security 5.5.2 iQCVAwUBOuCp2LnzJzdsy3QZAQHkQgP9HWZUijIK6dw/dWtVcZYhxBD6VBLA3ktW YS/Ovfq00Ool7GOaSRCv17YW6BTkhMU8cUCkS2a+OhJ/dyBqTYucdLqr5adX2+Ck L2rEF3vFmFbzlka9gMuE4fcqyKQRoaDGCXVHr62S3+ib68MTddUkxpPz+Qk8jHEU ZuVKhYg03go= =SnVv -----END PGP SIGNATURE-----