http://www.theregister.co.uk/content/8/18679.html
By: John Leyden
Posted: 02/05/2001 at 12:21 GMT
Microsoft's security patch for Outlook, which is designed to protect
users from the effects of another Love Bug-style virus, has come under
fire from no less a body than the US Air Force.
In a paper to be presented at a security workshop in June, an
assistant professor of computer science at the US Air Force Academy
will deliver a devastating critique of Microsoft's approach to
security in general and Outlook in particular.
Martin Carlisle will tell an audience of security experts that a
security patch to Outlook, which is designed to stop viruses spreading
via automated messages through requiring user's authorisation via a
dialog box, can be easily circumvented.
This "Object Model Guard" prompts a user with a dialogue box when an
external program tries to access a user's Outlook address book, a
trick used by the Love Bug and other similar viruses.
Carlisle said this idea has promise but Microsoft's implementation is
flawed.
"It is possible, with a small amount of code, to create a program that
hides and answers the dialog box automatically," said Carlisle.
In a paper to be presented at the workshop Carlisle explains how
Microsoft dismissed the significance of the potential vulnerability.
Its security team argues that to get around the dialog box they would
have to get executable code running on a victims machine, and if an
attacker could do that getting around the dialog box would be "the
least of your worries".
This, frankly astonishingly arrogant response, is given short shrift
by Carlisle: "The Microsoft Security Team seem to have missed the
significance of their own security patch because their view neglects
the ability of viruses of this class to replicate."
Carlisle and colleague (and co-author) Scott Studer have produced a
detailed rebuttal of Microsoft's argument and suggestions of
improvement to the dialogue box security, which involve protecting the
lowest level of an application.
In a statement we find hard to disagree with the researchers state
that reinforcing dialogs based security in Windows can only go so far.
"Given the current limitations of the Windows operating system, this
[improving dialogue box security] turns to be similar to trying to
secure a parked car at an airport. You can make it harder to break in
but you can never make you car totally secure."
The researchers said that Microsoft should consider modifying its
operating system in order to verify that messages received come from
users rather than other programs. Carlisle and Studer also cover a
variety of other ideas for dealing with Love Bug-style viruses (such
as blocking Visual Basic Scripting) and their paper is well worth a
read.
[USAF paper: Reinforcing Dialog-Based Security
http://www.usafa.af.mil/dfcs/papers/mcc/ieeesmc2001.html ]
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Received on Thu May 3 05:41 CDT 2001