K-061: Microsoft "Office HTML" & "IE" Script Vulnerabilities

PROBLEM:       Security vulnerabilities ("Office HTML") have been found in
               Office 2000 (Excel and PowerPoint) and in PowerPoint 97.
               Internet Explorer also has a vulnerability ("IE") that can be
               exploited using Access.
PLATFORM:      Those running:
                    Microsoft Excel 2000
                    Microsoft PowerPoint 97 and 2000
                    Microsoft Internet Explorer 5.5, 5.01 SP1, 5.01, 4.01 SP2
DAMAGE:        The first set of vulnerabilities allows malicious script code
               on a web page to cause a remotely hosted file to be saved on a
               visiting user's hard drive. The second vulnerability allows
               malicious script code on a web page to execute a VBA macro code
               in a remotely hosted file.
SOLUTION:      Apply the patches given below to eliminate the first set of
               vulnerabilities. A workaround for the second vulnerability is
               also given below.
VULNERABILITY  The risk is HIGH. The vulnerabilites and exploits have been
ASSESSMENT:    discussed in public forums.


[ Start of Microsoft advisory for "The Office HTML Script" vulnerability ]

Microsoft Security Bulletin (MS00-049)

Patch Available for "The Office HTML Script" Vulnerability and a
Workaround for "The IE Script" Vulnerability

Originally Posted: July 13, 2000

Summary

Microsoft has released a patch that eliminates a security vulnerability in
Microsoft (r) Office 2000 (Excel and PowerPoint) and in PowerPoint 97.
Microsoft has also documented a workaround that prevents the use of
Microsoft Access to exploit a vulnerability in Internet Explorer. A patch
for the latter vulnerability will be available soon and we will have an
update to this bulletin.

Frequently asked questions regarding this vulnerability and the patch can
be found at
http://www.microsoft.com/technet/security/bulletin/fq00-049.asp

Issue

Two vulnerabilities have recently been discovered, one affecting Microsoft
Office 2000, and PowerPoint 97, and the other Internet Explorer 4.01 SP2
and higher. We will refer to these issues as the "Office script" and "IE
script" vulnerabilities. The names refer to the product where the
vulnerability is present, but not necessarily how the vulnerability is
exploited.

  *) The Office HTML Script vulnerability, allows malicious script code on a
     web page to reference an Excel 2000 or PowerPoint file in such a way as
     to cause a remotely hosted file to be saved to a visiting user’s hard
     drive.

     This vulnerability can only be exploited by a reference to an Excel 2000
     or PowerPoint file; it cannot be exploited using Excel 97, Microsoft
     Word or a Microsoft Access file.

  *) The IE Script vulnerability, can allow malicious script code on a web
     page to reference a remotely hosted Microsoft Access file. The Microsoft
     Access file can in turn causes a VBA macro code in the file to be
     executed.

Affected Software Versions

  Microsoft Excel 2000
  Microsoft PowerPoint 97 and 2000
  Microsoft Internet Explorer 5.5, 5.01 SP1, 5.01, 4.01 SP2

Patch Availability

  Microsoft Excel 2000 and PowerPoint 2000:
  http://officeupdate.microsoft.com/2000/downloaddetails/Addinsec.htm

  Microsoft PowerPoint 97:
  http://officeupdate.microsoft.com/downloaddetails/PPt97sec.htm

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.

  Frequently Asked Questions: Microsoft Security Bulletin MS00-049,
  http://www.microsoft.com/technet/security/bulletin/fq00-049.asp

  Microsoft Knowledge Base (KB) articles:
  Q268365 (Excel 2000), Q268457 (PowerPoint 2000), Q268477 (PowerPoint 97)
  discusses "The Office HTML Script" vulnerability.

  The Microsoft Office Update Site, http://officeupdate.microsoft.com

  Microsoft TechNet Security web site,
  http://www.microsoft.com/technet/security/default.asp

Obtaining Support on this Issue

This is a fully supported patch. Information on contacting Microsoft
Product Support Services is available at
http://support.microsoft.com/support/contact/default.asp .

Revisions

  July 13, 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.

Last Updated July 18, 2000
(c) 2000 Microsoft Corporation. All rights reserved. Terms of use.

[ End of Microsoft advisory for "The Office HTML Script" vulnerability ]

----------------------------------------------------------------

[ Start of Microsoft workaround for "The IE Script" vulnerability ]

(The following was extracted from "Microsoft Security Bulletin
(MS00-049):  Frequently Asked Questions".)

What's the scope of the IE Script vulnerability?

The IE Script vulnerability allows any Microsoft Access database to
execute, if it is hosted on a web page that contains script code
referencing an Access .mdb file.

What causes the IE Script vulnerability?

Internet Explorer allows the execution of a remotely or locally hosted
Microsoft Access database that is referenced from a web page containing
script code. By default Microsoft Access files are treated as unsafe for
scripting; however, a certain script tag can be used to reference an
Access (.mdb) file and execute VBA macro code even if scripting has been
disabled in Internet Explorer.

What is the workaround for the IE Script vulnerability?

The workaround for this vulnerability is to set an Administrator password
for Microsoft Access. This will cause Microsoft Access to prompt the user
for the Administrator password before VBA code within an Access database
can be executed.

[ End of Microsoft workaround for "The IE Script" vulnerability ]

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