Re: Question for the Windows pros

[Paul Schmehl <pauls () utdallas edu>]

--On Wednesday, January 18, 2006 17:07:23 -0600 Frank Knobbe 
<frank () knobbe us> wrote:

> On Wed, 2006-01-18 at 16:16 -0600, Paul Schmehl wrote:
> > This means that the exposure, when granting the privilege, is as follows:
> > 1) If you can launch a process on the local machine AND
> > 2) The process has embedded credentials that are different from the user
> > launching the process THEN
> > 3) The user gains those credentials' privileges ***for the length of
> > that  process***
>
> Yup. So if your use has that right, any spyware the user downloads via
> IE can use that user right to elevate credentials **for the length of
> the malware installation**. Does that sound right? And does that sound
> like something you'd want to happen?
The spyware has to bring the credentials with it.  The user doesn't *have* 
the credentials.  It *gets* them from the process in question.  That's a 
bit different.  The user has the right to impersonate within the context of 
a process.  The process must already have the credentials to elevate, or 
the user gets nothing (if I'm understanding impersonation correctly.)
> If you give that right, or admin privs, why don't you limit that only to
> the duration of the software install? It sounded like you were planning
> on granting that user right and leaving it in place. If you only grant
> it temporarily, the exposure is not great, imho. (Remember, I've been
> liberated from Windows for a couple years now ;)
Do you know a way to programmatically grant rights, on the fly, and then 
take them away?  I know you can do this with RunAs, but that would require 
having an admin password, in the clear, and readable by Authenticated 
Users.  That ain't gonna happen.

As far as granting the privilege goes, *if* we do it, it will only be in 
place long enough to distribute the agents.  Then it will be removed.  But 
I'm reluctant to even do *that* until I'm certain I fully understand the 
ramifications.

Paul Schmehl (pauls () utdallas edu)
Adjunct Information Security Officer
University of Texas at Dallas
AVIEN Founding Member
http://www.utdallas.edu/ir/security/
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