RE: Question: Buffer Overrun in Microsoft Data Access Components Coul d Lead to Code Execution (Q329414)

From: Brad Bemis (
Date: 11/27/02

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    Date: Wed, 27 Nov 2002 08:51:27 -0800
    From: "Brad Bemis" <>
    To: "Harris, Ken" <>, "Kolde, Jennifer E." <>,

    Hash: SHA1

    I am a little leery about installing MDAC on client systems that do not
    require the full suite of services it provides.

    We have been updating our servers to MDAC 2.7, but rolling out the patch
    via logon/shutdown scripts to our client base. I am not entirely happy
    about the inherent flaw in this particular patch, but as I understand it,
    the flaw revolves around the new component control for RDS being replace by
    a pre-patched version.

    Has anybody taken a good hard look at what discernable changes take place
    when the pre-patched version is reintroduced?

    I'd be interested in the possibility of identifying specific elements of
    the control that can be tested by a script to determine which version is
    currently active and reapplying the patch if indeed the old control
    component has been reintroduced.

    Does anyone have any thoughts on this?

    - - Brad Bemis

    - -----Original Message-----
    From: Harris, Ken []
    Sent: Tuesday, November 26, 2002 12:16 PM
    To: 'Kolde, Jennifer E.'; ''
    Subject: RE: Question: Buffer Overrun in Microsoft Data Access
    Components Coul d Lead to Code Execution (Q329414)


    Thanks to all on focus-ms who replied, very good information indeed. It
    looks like the best practice is to upgrade across the board to MDAC 2.7
    (with proper testing) /unless/ there is a known inoperability requiring
    in which case the patch is our best (albeit weak) hope.

    Thanks again for your help,

    Ken Harris

    - -----Original Message-----
    From: Kolde, Jennifer E. []
    Sent: Tuesday, November 26, 2002 1:21 PM
    To: Harris, Ken; ''
    Subject: RE: Question: Buffer Overrun in Microsoft Data Access Components
    Coul d Lead to Code Execution (Q329414)

    Hello Ken,

    Sorry, trying again minus the digital signature.

    Microsoft also (quietly) lists upgrading to MDAC 2.7 as another fix. The
    information in the security bulletin is a bit confusing when you try to
    figure out just what is going on and where the vulnerability lies. The way
    read it, the problem lies both the version of MDAC used AND a specific
    ActiveX control that is vulnerable. You are correct that even if you patch
    your current version of MDAC, the vulnerable ActiveX control could still be

    MDAC 2.7 is not vulnerable to the problem according to Microsoft, so if you
    upgrade to 2.7, the ActiveX issue becomes moot.

    A possible concern is that, because MDAC brokers your database requests,
    upgrade may affect your application based on any differences between the
    older MDAC components and 2.7. I'm not a database guru (IANADBG???) so
    you'd have to research/test this on your own.

    MDAC can be downloaded from, which also
    includes documentation / changelogs for different versions. I did install
    MDAC 2.7 on a Win2K Server with no ill effects, but the Server is not doing
    anything specifically database-related.


    - -----Original Message-----
    From: Harris, Ken []
    Sent: Friday, November 22, 2002 2:39 PM
    To: ''
    Subject: Question: Buffer Overrun in Microsoft Data Access Components Coul
    Lead to Code Execution (Q329414)

    Hello all on focus-ms,

    Was wondering if anyone had figured out the best practice fix to the
    security flaw described here:

    The reason I ask is that Microsoft does not seem to show much confidence in
    this patch; e.g. in the Caveats section, it is implied that if a webpage
    references the older, pre-patch RDS control, dependent upon the IE security
    settings they will either be prompted to install the control, or it will be
    installed silently if Microsoft is added to the Trusted Publishers list.

    We happen to have a mission-critical custom webapp used internally which
    does use RDS, and is in the Trusted Sites zone on our workstations.
    I can't guarantee that the developers of this solution will get around to
    patching the server on which this runs, or changing the references in the
    ASP pages. Microsoft is NOT in the Trusted Publishers list on our
    workstation build, although there is nothing keeping our users from
    "Always trust content from Microsoft".

    Am I right in assuming that even if we deploy the patch to our
    unless the patch is also applied to the webapp and the code is changed, the
    vulnerable control could be reinstalled and the workstation would be again
    vulnerable to this attack from a malicious website? Is there a better
    option? The client/server nature of this vulnerability makes me think that
    we may see a worm written to exploit it soon.

    Thanks in advance.


    Ken Harris

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