The Invisible Things Lab's blog

The wait is over. The slides are here. The press release is here. Unless you're a chipset/BIOS engineer kind of person, I strongly recommend reading the press release first, before opening the slides.

So, the "Ring -3 Rootkit" presentation is about vPro/AMT chipset compromises. The "Attacking Intel BIOS" presentation is about exploiting a heap overflow in BIOS environment in order to bypass reflashing protection, that otherwise allows only Intel-signed updates to be flashed.

We will publish the code some time after get back from Vegas.

Enjoy.

ps. Let me remind my dear readers that all the files hosted on the ITL website are not digitally signed and are served over a plaintext connection (HTTP). In addition, the ITL's website is hosted on a 3rd party provider's server, on which we have totally no control (which is the reason why we don't buy an SSL certificate for the website). Never trust unsigned files that you download from the Internet. ITL cannot be liable for any damages caused by the files downloaded from our website, unless they are digitally signed.

As promised, the paper and the proof of concept code has just been posted on the ITL website here.

A quote from the paper:

In this paper we have described practical exploitation of the CPU cache poisoning in order to read or write into (otherwise protected) SMRAM memory. We have implemented two working exploits: one for dumping the content of SMRAM and the other one for arbitrary code execution in SMRAM. This is the third attack on SMM memory our team has found within the last 10 months, affecting Intel-based systems. It seems that current state of firmware security, even in case of such reputable vendors as Intel, is quite unsatisfying.

The potential consequence of attacks on SMM might include SMM rootkits [9], hypervisor compromises [8], or OS kernel protection bypassing [2].

Don't worry, the shellcode we use in the exploit is totally harmless (have really no idea how some people concluded we were going to release an SMM rootkit today?) — it only increases an internal counter on every SMI and jumps back to the original handler. If you want something more fancy, AKA SMM rootkits, you might want to re-read Sherri's and Shawn's last year's Black Hat paper and try writing something they describe there.

The attack presented in the paper has been fixed on some systems according to Intel. We have however found out that even the relatively new boards, like e.g. Intel DQ35 are still vulnerable (the very recent Intel DQ45 doesn't seem to be vulnerable though). The exploit attached is for DQ35 board — the offsets would have to be changed to work on other boards (please do not ask how to do this).

Keep in mind this is a different SMM attack than the one we mentioned during our last month's Black Hat presentation on TXT bypassing (the VU#127284). We are planning to present that other attack at the upcoming Black Hat Vegas. Hopefully this will not be the only one thing that ITL will entertain you with in Vegas — Alex and Rafal are already working now on something even cooler (and even lower level) for the show, so cross your fingers!

And good luck to Loic with his presentation that is about to start just now...

The new press release covering the basic details about our TXT attack is here.

The paper is here.

The slides converted to a PDF format are here. There is also an original version of slides in the Keynote format here for the Mac people. And for all the other people who don't use Mac, but still value the aesthetics (?!), I have also generated a QuickTime clickable movie out from the Keynote slides -- it can be found here, but it weighs 80MB.

Enjoy.