From secnotif@MICROSOFT.COM Thu Feb 17 01:51:43 2000 From: Microsoft Product Security Resent-From: mea culpa To: MICROSOFT_SECURITY@ANNOUNCE.MICROSOFT.COM Resent-To: jericho@attrition.org Date: Wed, 16 Feb 2000 18:04:05 -0800 Subject: Microsoft Security Bulletin (MS00-009) 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 (MS00-009) -------------------------------------- Patch Available for "Image Source Redirect" Vulnerability Originally Posted: February 16, 2000 Summary ======= Microsoft has released a patch that eliminates a security vulnerability in Microsoft® Internet Explorer. The vulnerability could allow a malicious web site operator to read - but not add, change or delete - certain types of files on the computer of a visiting user. Frequently asked questions regarding this vulnerability can be found at http://www.microsoft.com/technet/security/bulletin/fq00-009.asp. Issue ===== When a web server navigates a window from one domain into another one, the IE security model checks the server's permissions on the new page. However, it is possible for a web server to open a browser window to a client-local file, then navigate the window to a page that is in the web site's domain in such a way that the data in the client-local file is accessible to the new window. The data would only be accessible to the new window for a very brief period, but the result is that it could be possible for a malicious web site operator to view files on the computer of a visiting user. The web site operator would need to know (or guess) the name and location of the file, and could only view file types that can be opened in a browser window. Affected Software Versions ========================== Microsoft Internet Explorer 4.0 and 4.01. Microsoft Internet Explorer 5 and 5.01. Patch Availability ================== http://windowsupdate.microsoft.com http://www.microsoft.com/windows/ie/security/patch5.asp NOTE: Microsoft produces security patches for Internet Explorer 4.01 SP2 and higher. In the event that this package is applied to Internet Explorer 4.01 SP1, the package states that a fix is not needed. This message is incorrect, as the vulnerability does exist on Internet Explorer 4.01 SP1 or any earlier release. If you are using Internet Explorer 4.01 SP1 or any earlier release, please upgrade to the latest version of Internet Explorer to resolve this issue. 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. - Microsoft Security Bulletin MS00-009: Frequently Asked Questions. - Microsoft Knowledge Base (KB) article. A link will be posted to http://www.microsoft.com/technet/Security/Bulletin/ms00-009.asp as soon as the article is available. - Microsoft Security Advisor web site, http://www.microsoft.com/security/default.asp Obtaining Support on this Issue =============================== This is a fully supported patch. Information on contacting Microsoft Technical Support is available at http://support.microsoft.com/support/contact/default.asp Revisions ========= February 16, 2000: 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) 2000 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.