Microsoft Security Bulletin (MS99-037) Patch Available for "ImportExportFavorites" Vulnerability Released: September 24, 1999 Summary On September 10, 1999, Microsoft released the original version of this bulletin, in order to provide a workaround for a security 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. Microsoft has completed a patch that completely eliminates the vulnerability, and has re-released this bulletin in order to advise customers of its availability. In addition to eliminating the "ImportExportFavorites" vulnerability, the patch also eliminates a security vulnerability posed by several ActiveX controls that ship as part of Internet Explorer 4.01 and 5. 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. The patch restores correct operation to the ImportExportFavorites() method. In addition, the patch addresses security problems posed by several ActiveX controls. The specific controls and the actions taken are discussed in the FAQ. Affected Software Versions Microsoft Internet Explorer 4.01 and 5 Patch Availability Internet Explorer 4.01 for Intel: ftp://ftp.microsoft.com/peropsys/ie/ie-public/fixes/usa/IE401/ImportExportFavorites-fix/x86/q241361.exe Internet Explorer 4.01 for Alpha: ftp://ftp.microsoft.com/peropsys/ie/ie-public/fixes/usa/IE401/ImportExportFavorites-fix/Alpha/q241361.exe Internet Explorer 5 for Intel: ftp://ftp.microsoft.com/peropsys/ie/ie-public/fixes/usa/IE50/ImportExportFavorites-fix/x86/q241361.exe Internet Explorer 5 for Alpha: ftp://ftp.microsoft.com/peropsys/ie/ie-public/fixes/usa/IE50/ImportExportFavorites-fix/Alpha/q241361.exe NOTE: The patch also will be available shortly via WindowsUpdate. When this happens, we will amend this bulletin to provide specific link information. 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 Knowledge Base (KB) article Q241361, Update available to disable ActiveX controls and the ImportExport Security Issues, http://support.microsoft.com/support/kb/articles/q241/3/61.asp. (Note: It may take 24 hours from the posting of this bulletin for the KB article to appear) 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 the ImportExportFavorites issue to our attention. Microsoft acknowledges Shane Hird of Australia and Richard Smith of Phar Lap Software (http://www.pharlap.com/) for reporting the unsafe ActiveX controls to us. Revisions September 10, 1999: Bulletin Created. September 24, 1999: Bulletin revised to provide patch information and discuss ActiveX controls. -------------------------------------------------------------------------------- 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. © 1999 Microsoft Corporation. All rights reserved. Terms of Use.