__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Microsoft Outlook View Control Exposes Unsafe Functionality [Microsoft Security Bulletin MS01-038] July 17, 2001 19:00 GMT Number L-113 Revised August 17, 2001 ______________________________________________________________________________ PROBLEM: The Microsoft Outlook View Control is an Active X control that allows Outlook mail folders to be viewed via web pages. The control should only allow passive operations such as viewing mail or calendar data. There is an unsafe function within this control that can allow the web page to manipulate Outlook data. PLATFORM: Microsoft Outlook 98, 2000, and 2002. DAMAGE: By exposing the function that can allow the web page to manipulate Outlook data, it permits an attacker to delete mail, change calendar information, possibly run arbitrary code on a user's machine, or take any other action through Outlook. SOLUTION: A patch is now available. ______________________________________________________________________________ VULNERABILITY The risk is LOW. The vulnerability provides no capability for ASSESSMENT: an attacker to force a user to visit a web page that exploits it. ______________________________________________________________________________ [****** Start Microsoft Security Bulletin ******] - ---------------------------------------------------------------------- Title Outlook View Control Exposes Unsafe Functionality Released 12 July 2001 Revised 16 August 2001 (version 2.0) Software Outlook 2002, 2000, and 98 Impact Run code of attacker's choice Bulletin MS01-038 Microsoft encourages customers to review the Security Bulletin at http//www.microsoft.com/technet/security/bulletin/MS01-038.asp. - ---------------------------------------------------------------------- Reason for Revision ==================== The original version of the bulletin advised customers of a workaround procedure that could be used while a patch was under development. We have now completed the patch, and have re-released this bulletin to advise customers of its availability. Issue ====== On July 12, 2001, Microsoft released the original version of this bulletin, to advise customers of a vulnerability affecting Microsoft Outlook and to recommend that they temporarily use an administrative procedure to protect their systems. A patch that eliminates the vulnerability is now available. An updated version of the bulletin was released on August 16, 2001, to announce the availability of the patch and to advise customers that the administrative procedure is no longer needed. The Microsoft Outlook View Control is an ActiveX control that allows Outlook mail folders to be viewed via web pages. The control should only allow passive operations such as viewing mail or calendar data. In reality, though, it exposes a function that could allow the web page to manipulate Outlook data. This could enable an attacker to delete mail, change calendar information, or take virtually any other action through Outlook including running arbitrary code on the user's machine. Hostile web sites would pose the greatest threat with respect to this vulnerability. If a user could be enticed into visiting a web page controlled by an attacker, script or HTML on the page could invoke the control when the page was opened. The script or HTML could then use the control to take whatever action the attacker desired on the user's Outlook data. It also would be possible for the attacker to send an HTML e-mail to a user, with the intent of invoking the control when the recipient opened the mail. However, the Outlook E-mail Security Update, that automatically installs as part of Outlook 2002 would thwart such an attack. The Update causes HTML e-mails to be opened in the Restricted Sites Zone, where ActiveX controls are disabled by default. Mitigating Factors ==================== - The newly-released Outlook E-mail Security Update that is integrated into Outlook 2002 would also prevent this vulnerability from being exploited via e-mail in all affected Outlook versions. - The vulnerability provides no capability for the attacker to force a user to visit a web page that exploits it. Patch Availability =================== - A patch is available to fix this vulnerability. Please read the Security Bulletin http//www.microsoft.com/technet/security/bulletin/ms01-038.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 Center, 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. 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