[Dailydave] POC 2007 notes v 2
Joanna Rutkowska
joanna at invisiblethings.org
Fri Nov 16 06:06:15 EST 2007
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Dave Aitel wrote:
> Likewise the talk on Bios and VMWare vulnerabilities was interesting.
> Sun Bing had one demo where he got local Administrator on an XP SP2
> guest by using a VMWare vulnerability (unreleased).
On a *guest*? Are you saying it was a host->guest "attack"? If so, there
are like millions of ways to do that, and niether of them requires any
vulnerability in a VMM... It's just, that in case of any type II VMM, if
you're on the host, you can do anything you want with the guest, no big
deal. Or am I missing something?
> He also had several guest->host escape techniques (VMWare dieing due
> to memory access failures and such) - no working PoC here, just
> crashes.
We saw many bugs in various VMMs -- just a couple of references:
* A paper from Tavis Ormandy (Google) on how most VMMs couldn't (over
the time when the paper was written) properly handle many non-standard
I/Os and also properly parse some instructions (April 2007),
* Two interesting bugs by Rafal Wojtczuk affecting VMWare and Virtual MS
Server products that could potentially allow for guest escape (September
2007),
* A bug by Joris van Rantwijk affecting Xen 3, that allows for code
execution in dom0 from any other domain (September 2007).
This is all very good and interesting -- it's a very valuable argument
in convincing people that hypervisors (VMMs) should be extremly thin.
And thin means just a few thousands of LOC, not 3MB of code (Hi 3i!).
After all the industry didn't want to adapt the micro-kernel approach
and we all pay the price today (all those rootkits, etc), so at least
lets try not to make the same mistake again with VMMs...
However, I can't really understand why people go to a conference and
show a bunch of non-exploitable (by them) bugs without even giving any
details of the bug itself... Is it like: "Hey, I can use I/O fuzzer!"?
Or maybe I'm too conservative? (getting old and stuff)? :)
> The Bios tricks were interesting as well - essentially
> they were documentation on how to install useful Bios rootkits or
> perform a really annoying DoS by flipping one of the hardware bits
> (would require complete power drain to reset).
Can you elaborate more on this and how that relates to what John Heasman
showed at BH Federal in 2006?
joanna.
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