Re: Exploiting memory corruption vulnerabilities on Internet Explorer 8

[Jared DeMott <jared.demott () harris com>]

Freddie Vicious wrote:
> Microsoft has released Internet Explorer 8 on March 19, 2009 and up to
> now there's no reliable method to exploit memory corruption
> vulnerabilities on it?
>
> I mean, on IE6 and IE7 we had SkyLined heap spray technique, first
> seen in the IFRAME overflow exploit [1] which have been used by almost
> every IE memory corruption exploit so far. Internet Explorer 8 was
> enhanced with DEP and ASLR protections, making heap spray useless.
> Then Mark Dowd and Alexander Sotirov published their great paper -
> Bypassing Browser Memory Protections [2] providing some excellent
> techniques, mainly the .NET binary technique which bypasses DEP and
> ASLR which was used by Nils on the latest Pwn2Own to own Internet
> Explorer 8 RC (Release Candidate) [3] and was used to mass-exploit
> other vulnerabilities [4]. One day after Nils owned IE8RC, Microsoft
> released Internet Explorer 8 RTM and blocked the option to load .NET
> DLL’s from Internet zone and Restricted sites zone. Due to the fact
> that most of IE exploitation doesn’t occur in Intranet/Trusted
> sites/Local machine zone, this makes the .NET DLL technique irrelevant
> most of the times.
> So my question is - Is there no reliable method to exploit memory
> corruption vulnerabilities in Internet Explorer 8?
I'm not aware of any catch-all technique just for IE8, though there are
a few common ones like return oriented programming.  Application
specific techniques are also common when third party extensions are
involved.
> [1] http://milw0rm.com/exploits/612
> [2] http://taossa.com/archive/bh08sotirovdowd.pdf
> [3]
> http://dvlabs.tippingpoint.com/blog/2009/03/18/pwn2own-2009-day-1---safari-internet-explorer-and-firefox-taken-down-by-four-zero-day-exploits
> [4] http://milw0rm.com/exploits/8969
>
> -- 
> Best wishes,
> Freddie Vicious


-- 
__________________________________________
Jared D. DeMott
Principal Security Researcher

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