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Thread: CERT Advisory CA-2002-04 Buffer Overflow in Microsoft Internet Explorer

  1. #1
    Senior Member
    Join Date
    Sep 2001

    Unhappy CERT Advisory CA-2002-04 Buffer Overflow in Microsoft Internet Explorer


    CERT Advisory CA-2002-04 Buffer Overflow in Microsoft Internet Explorer

    Original release date: February 25, 2002
    Last revised: --
    Source: CERT/CC

    A complete revision history can be found at the end of this file.

    Systems Affected

    * Microsoft Internet Explorer
    * Microsoft Outlook and Outlook Express
    * Other applications that use the Internet Explorer HTML rendering


    Microsoft Internet Explorer contains a buffer overflow vulnerability
    in its handling of embedded objects in HTML documents. This
    vulnerability could allow an attacker to execute arbitrary code on the
    victim's system when the victim visits a web page or views an HTML
    email message.

    I. Description

    Internet Explorer supports the directive, which can be used to
    include arbitrary objects in HTML documents. Common types of embedded
    objects include multimedia files, Java applets, and ActiveX controls.
    The SRC attribute specifies the source path and filename of an object.
    For example, a MIDI sound might be embedded in a web page with the
    following HTML code:

    Internet Explorer uses attributes of the directive and MIME
    information from the web server to determine how to handle an embedded
    object. In most cases, a separate application or plugin is used.

    A group of Russian researchers, SECURITY.NNOV, has reported that
    Internet Explorer does not properly handle the SRC attribute of the
    directive. An HTML document, such as a web page or HTML email
    message, that contains a crafted SRC attribute can trigger a buffer
    overflow, executing code with the privileges of the user viewing the
    document. Microsoft Internet Explorer, Outlook, and Outlook Express
    are vulnerable. Other applications that use the Internet Explorer HTML
    rendering engine, such as Windows compiled HTML help (.chm) files and
    third-party email clients, may also be vulnerable.

    The CERT/CC is tracking this vulnerability as VU#932283, which
    corresponds directly to the "buffer overrun" vulnerability described
    in Microsoft Security Bulletin MS02-005.

    This vulnerability has been assigned the CVE identifier CAN-2002-0022.

    II. Impact

    By convincing a user to view a malicious HTML document, an attacker
    can cause the Internet Explorer HTML rendering engine to execute
    arbitrary code with the privileges of the user who viewed the HTML
    document. This vulnerability could be exploited to distribute viruses,
    worms, or other malicious code.

    III. Solution

    Apply a patch

    Microsoft has released a cumulative patch for Internet Explorer that
    corrects this vulnerability and several others. For more information
    about the patch and the vulnerabilities, please see Microsoft Security
    Bulletin MS02-005:

    Disable ActiveX Controls and Plugins

    In Internet Explorer, plugins may be used to view, play, or otherwise
    process embedded objects. The execution of embedded objects is
    controlled by the "Run ActiveX Controls and Plugins" security option.
    Disabling this option will prevent embedded objects from being
    processed, and will therefore prevent exploitation of this

    According to MS02-005:

    The vulnerability could not be exploited if the "Run ActiveX
    Controls and Plugins" security option were disabled in the Security
    Zone in which the page was rendered. This is the default condition
    in the Restricted Sites Zone, and can be disabled manually in any
    other Zone.

    At a minimum, disable the "Run ActiveX Controls and Plugins" security
    option in the Internet Zone and the zone used by Outlook or Outlook
    Express. The "Run ActiveX Controls and Plugins" security option is
    disabled in the "High" zone security setting. Instructions for
    configuring the Internet Zone to use the "High" zone security setting
    can be found in the CERT/CC Malicious Web Scripts FAQ:

    Apply the Outlook Email Security Update

    Another way to effectively disable the processing of ActiveX controls
    and plugins in Outlook is to install the Outlook Email Security
    Update. The update configures Outlook to open email messages in the
    Restricted Sites Zone, where the "Run ActiveX Controls and Plugins"
    security option is disabled by default. In addition, the update
    provides further protection against malicious code that attempts to
    propagate via Outlook.

    * Outlook 2002 and Outlook Express 6
    The functionality of the Outlook Email Security Update is included
    in Outlook 2002 and Outlook Express 6.
    * Outlook 2000
    * Outlook 98

    Appendix A. - Vendor Information

    This appendix contains information provided by vendors for this
    advisory. When vendors report new information to the CERT/CC, we
    update this section and note the changes in our revision history. If a
    particular vendor is not listed below, we have not received their


    Microsoft has released a Security Bulletin and a Knowledge Base
    Article addressing this vulnerability:
    * Security Bulletin MS02-005
    * Knowledge Base Article Q317731;en-us;Q317731


    Our email client Mulberry does not use the core HTML rendering engine
    library for its HTML display, and so is not affected by the bug in
    that library. Having looked at the details of this alert I can also
    confirm that our own HTML rendering engine is not affected by this, as
    it ignores the relevant tags.

    Appendix B. - References



    The CERT/CC thanks ERRor and DarkZorro of domain Hell and 3APA3A of
    SECURITY.NNOV for reporting this issue to us.

    Author: Art Manion

    This document is available from:

    CERT/CC Contact Information

    Phone: +1 412-268-7090 (24-hour hotline)
    Fax: +1 412-268-6989
    Postal address:
    CERT Coordination Center
    Software Engineering Institute
    Carnegie Mellon University
    Pittsburgh PA 15213-3890

    CERT/CC personnel answer the hotline 08:00-17:00 EST(GMT-5) /
    EDT(GMT-4) Monday through Friday; they are on call for emergencies
    during other hours, on U.S. holidays, and on weekends.

    Using encryption

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    If you prefer to use DES, please call the CERT hotline for more

    Getting security information

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    send email to Please include in the body of your

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    * "CERT" and "CERT Coordination Center" are registered in the U.S.
    Patent and Trademark Office.

    Any material furnished by Carnegie Mellon University and the Software
    Engineering Institute is furnished on an "as is" basis. Carnegie
    Mellon University makes no warranties of any kind, either expressed or
    implied as to any matter including, but not limited to, warranty of
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    Conditions for use, disclaimers, and sponsorship information

    Copyright 2002 Carnegie Mellon University.

    Revision History
    February 25, 2002: Initial release

    Version: PGP 6.5.8

    -----END PGP SIGNATURE-----

  2. #2
    Senior Member
    Join Date
    Dec 2001
    more of these every day. Since the US govt got nowhere with them maybe the Euro commission will. Msoft I mean.

  3. #3
    AntiOnline Senior Member souleman's Avatar
    Join Date
    Oct 2001
    Flint, MI
    The microsoft post (below) was posted February 11. This is the 25th. This just goes to show how slow CERT has become. Yet CERT used to be the First place that administrators went to find out about patches. Now, your system should be patched before you get the message from CERT.
    \"Ignorance is bliss....
    but only for your enemy\"
    -- souleman

  4. #4
    Senior Member
    Join Date
    Dec 2001
    yeah I used to go to cert everyday but now it has slipped...

  5. #5
    The CERT/CC is tracking this vulnerability as VU#932283
    heh and thats just the number of the vunerability found that day for a micro$oft product


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