Microsoft Security Bulletin (MS00-009)

[secnotif () MICROSOFT COM (Microsoft Product Security)]

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.