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From: B.Goodman (bmgoodmanva_at_yahoo.com)
Date: Fri Sep 06 2002 - 13:47:37 CDT

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    ('binary' encoding is not supported, stored as-is) In-Reply-To: <20020903115939.14711.qmailmail.securityfocus.com>

    Hey, Woody, can this exploit parse environment variables? In WOW #7.42,
    you say the mitigating factor is that "Alice has to know the precise name
    of the file she wants to retrieve", but your example of c:\Documents and
      Settings\Woody\Local Settings\Application
    Data\Microsoft\Outlook\Outlook.pst becomes a LOT more capable if I could
    substitute %userprofile%\Local Settings\Application
    Data\Microsoft\Outlook\Outlook.pst instead!

    I don't have Outlook 97 readily available or I would test this myself.

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    >From: Woody Leonhard <woodywopr.com>
    >To: bugtraqsecurityfocus.com
    >Subject: Re: Security side-effects of Word fields
    >
    >In-Reply-To: <20020826212322.1137.qmailmail.securityfocus.com>
    >
    >Alex -
    >
    >You've come up with a very clever application of field codes - one that I
    >had never considered. I'm working with Word 2000 SR-1a and Word 2002 SP-
    >2. I've had a chance to converse with Dr. Vesselin Bontchev, who's using
    >Word 97. So far, here's what I've been able to pin down:
    >
    >The "Document collaboration spyware" attack is, as you describe, far more
    >ominous if the {INCLUDETEXT} field fires automatically.
    >
    >Apparently, Word 97 behaves precisely as you describe - in particular, if
    >the
    >
    >{ IF { INCLUDETEXT { IF { DATE } = { DATE } "c:\\a.txt" "c:\\a.txt" } \*
    >MERGEFORMAT } = "" "" \* MERGEFORMAT }
    >
    >field is the last field in a document, it's automatically updated when
    >the document is opened. That's a huge security hole, in my opinion.
    >
    >Word 2000 SR-1a and Word 2002 SP-2 don't behave the same way. In the
    >later versions, I can only get two fields to update automatically: {DATE}
    >and {TIME}. They're updated automatically when the document is opened, no
    >matter where they sit in the document. I couldn't get any combination of
    >{if {date}...} or {includetext {date} ...} fields to update automatically
    >in 2000 or 2002.
    >
    >That said, I did stumble onto a weird combination of fields that seems to
    >pull some outside text into the document automatically, even in Word 2000
    >and Word 2002. I've contacted Microsoft about the problem - going to give
    >them a chance to solve it before I talk about it - and will keep you
    >posted as I learn more.
    >
    >The "oblivious signing" attack you describe can be similarly triggered
    >automatically using judicious combinations of {if} and {date} fields -
    >but only in Word 97. There may be a way to do it automatically in Word
    >2000 and/or 2002, but I haven't been able to come up with a combination
    >that works.
    >
    >If you have to rely on the victim manually updating all the fields in a
    >document, the threat is much less ominous (in my opinion, anyway). But
    >it's worth noting that printing a document in any version of Word will
    >trigger an update of all the fields in the document, unless the user has
    >specifically clicked Tools | Options | Print | Printing Options and
    >unchecked the box marked "Update fields".
    >
    >I'll be following this security hole closely in "Woody's Office Watch"
    >over the next few weeks.
    >
    >- Woody
    >