Microsoft Security Bulletin (MS99-030)
--------------------------------------
Updated Patch Available for Office "ODBC Vulnerabilities"
Originally Posted: August 20, 1999
Revised: August 23, 1999
Re-released: October 08, 1999
Summary
=======
Microsoft has released an updated patch that eliminates security
vulnerabilities in the Microsoft(r) Jet database engine. A patch originally
was released in August 1999, but an additional variant of one
vulnerability, the "Text I-ISAM" vulnerability, was subsequently
discovered. The new variant could allow a database query to delete files on
a user's computer. This bulletin has been re-released to discuss the
vulnerabilities in their entirety.
The vulnerabilities in total could affect any application that runs atop
Jet, and could allow a database query to take virtually any action on a
user's computer. Microsoft recommends that all customers who are running
applications that use Jet, especially users of Microsoft Office 97 and
Office 2000, install the patch. Customers who applied the original patch
should apply the new one to ensure that they are fully protected against
all variants. Customers who did not previously apply the patch need only
apply the new version.
Issue
=====
Jet is a database engine used by Microsoft products such as Microsoft
Office97 and Office2000. Two vulnerabilities exist in Jet:
- The "VBA Shell" vulnerability, which affects all versions of
Jet except Jet 4.0. An operating system command embedded within
a database query could be executed when the query is processed.
This would allow a spreadsheet, database, or other application
file that contained such a query to take virtually any action
on the user's computer when the query was executed.
- The "Text I-ISAM" vulnerability, which affects all versions of
Jet. Jet provides a way to modify the contents of text files, as a
way of allowing data exchange between it and other systems. However,
a malicious user could use this capability to modify system files via a
database query. The original patch for this vulnerability allowed "drop
table" operations to be used, which could allow files on the user's
computer to be deleted; the new patch eliminates this variant.
Microsoft Office uses the Jet engine, and Office users are particularly at
risk from these vulnerabilities. (The "VBA Shell" vulnerability affects all
versions of Office prior to Office2000, and also affects one member of the
Office2000 suite, Access2000. The "Text I-ISAM" vulnerability affects all
versions of Office). The vulnerabilities are an especially serious threat
to Office users for three reasons:
- Scenarios for exploiting these vulnerabilities via Office documents
are publicly known.
- The ubiquity of Office would make it an attractive target for
mounting attacks via these vulnerabilities.
- The ability of Office documents to perform Document Object
Hosting would permit users to be attacked simply by visiting a
malicious user's web site. (Please note that a tool that prevents this
attack was included as part of the original patch for this issue, so
customers who used it are no longer vulnerable to attacks via web
pages).
Microsoft Jet also is used by several other Microsoft products, as well as
many third party applications. However, the ability to exploit this
vulnerability through these products is highly dependent on the specific
application. Although Microsoft has not identified a means of exploiting
these vulnerabilities through any Microsoft products except Office, we
recommend that all customers who have Microsoft Jet installed on their
computer update it. This will ensure that they are protected against any
possible attacks that may be developed.
Affected Software Versions
==========================
- Microsoft Jet, all versions
NOTE: Jet serves as the database engine for a number of Microsoft products,
including but not limited to:
- Microsoft Office
- Microsoft Visual Studio
- Microsoft Publisher
- Microsoft Streets & Trips
Jet also serves as the database engine for many third-party software
products. The patch does not require any change to any of the applications
that use Jet; instead, it operates directly on the Jet database engine and
restores proper functionality to it.
NOTES:
- The above web site provides separate pages for Office97 and
Office2000. This is done in order to provide specific information
about the vulnerabilities affecting the products. The patch for
Office97 and Office2000 (and indeed for all affected products) is
exactly the same, and both pages link to exactly the same patch.
The patch will determine what version(s) of Jet are present on
the machine and apply all of the needed corrections.
- The patch is suitable for use by all language packs.
- The patch applies to Jet 3.5 and all subsequent versions. Older
versions of Jet are no longer supported, and we recommend that
affected customers upgrade to a supported version.
- The patch is suitable for widespread deployment via Microsoft(r)
Systems Management Server(r). Users who wish to manually apply
patches for specific versions of Jet should consult the FAQ for
information on how to do this.
More Information
================
Please see the following references for more information related to this
issue. Please note that it may take 24 hours from the original posting of
this bulletin for all of the KB articles to be visible on the Microsoft web
site.
Acknowledgments
===============
Microsoft acknowledges Juan Carlos Cuartango of Spain for bringing this
issue to our attention and identifying the additional variant of the "Text
I-ISAM" vulnerability.
Revisions
=========
- August 20, 1999: Bulletin Created.
- August 23, 1999: Revised to provide updated patch location
- October 08, 1999: Re-released to provide patch that corrects
additional variants of the "Text I-ISAM" vulnerability
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