Return-Path: owner-microsoft_security@ANNOUNCE.MICROSOFT.COM X-Mailer: Internet Mail Service (5.5.2524.0) Message-ID: Date: Fri, 10 Sep 1999 17:52:24 -0700 Sender: Microsoft Product Security Notification Service From: Microsoft Product Security Subject: Microsoft Security Bulletin (MS99-037) To: MICROSOFT_SECURITY@ANNOUNCE.MICROSOFT.COM The following is a Security Bulletin from the Microsoft Product Security Notification Service. Please do not reply to this message, as it was sent from an unattended mailbox. ******************************** Microsoft Security Bulletin (MS99-037) -------------------------------------- Patch Available for "ImportExportFavorites" Vulnerability Originally Posted: September 10, 1999 Summary ======= Microsoft has learned of a vulnerability in Microsoft Internet Explorer 5 that could allow a malicious web site operator to take inappropriate action on the computer of a person who visited the site. Customers can immediately protect themselves against this vulnerability by disabling Active Scripting in IE 5, as discussed in the FAQ. Microsoft also is developing a patch that will restore safe operation to the affected feature; when the patch is available, this bulletin will be re-released. Frequently asked questions regarding this vulnerability can be found at http://www.microsoft.com/security/bulletins/MS99-037faq.asp Issue ===== IE 5 includes a feature that allows users to export a list of their favorite web sites to a file, or to import a file containing a list of favorite sites. The method that is used to perform this function, ImportExportFavorites(), should only allow particular types of files to be written, and only to specific locations on the drive. However, it is possible for a web site to invoke this method, bypass this restriction and write files that could be used to execute system commands. The net result is that a malicious web site operator potentially could take any action on the computer that the user would be capable of taking. This vulnerability would chiefly affect workstations that are connected to the Internet. As an immediate measure, customers can prevent the ImportExportFavorites function from operating by disabling Active Scripting, as discussed in the FAQ. A patch that restores correct operation is under development and will be delivered shortly. Affected Software Versions ========================== - Microsoft Internet Explorer 5 Workaround ========== The vulnerability can be prevented by disabling Active Scripting. The FAQ contains details on how to do this. More Information ================ Please see the following references for more information related to this issue. - Microsoft Security Bulletin MS99-037: Frequently Asked Questions, http://www.microsoft.com/security/bulletins/MS99-037faq.asp. - Microsoft Security Advisor web site, http://www.microsoft.com/security/default.asp. Obtaining Support on this Issue =============================== Information on contacting Microsoft Technical Support is available at http://support.microsoft.com/support/contact/default.asp. Acknowledgments =============== Microsoft acknowledges Georgi Guninski for bringing this issue to our attention. Revisions ========= - September 10, 1999: 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. (c) 1999 Microsoft Corporation. All rights reserved. Terms of Use. ******************************************************************* You have received this e-mail bulletin as a result of your registration to the Microsoft Product Security Notification Service. You may unsubscribe from this e-mail notification service at any time by sending an e-mail to MICROSOFT_SECURITY-SIGNOFF-REQUEST@ANNOUNCE.MICROSOFT.COM The subject line and message body are not used in processing the request, and can be anything you like. For more information on the Microsoft Security Notification Service please visit http://www.microsoft.com/security/services/bulletin.asp. For security-related information about Microsoft products, please visit the Microsoft Security Advisor web site at http://www.microsoft.com/security.