November 2012 Archives

lundi 26 novembre 2012, 17:00:51 (UTC+0100)

ZeroNights 2012: Opinions and links

I went in Moscow last week as a speaker for ZeroNights, one of the big Russian conferences. This was a really fun!

First, the conference organization. I found a single negative point: some content was exclusively in Russian (a few conferences + the opening and closing talks). Given my lack of knowledge of this language, I spent this time chatting with others, even if I'd have like understand (among others) the talk about the Yandex bug bounty. I like the 2 (or 3) days format which allows to interact a lot with other people. A single day event is usually too short for a good “hallway track”. And two parallel tracks + workshops is in my opinion enough to keep people busy most of the day. A live RU <=> EN translation was available for Track 1. This was working surprisingly well, even if it's quite destabilizing as a speaker, mostly because of the delay. The organizers tried to have a nice XML lineup. This was perfectly done, with what I believe to be the most diverse, technical, realist and eye-opening conferences about XML security. I submitted to this CFP for this very reason, and I'm glad to have been part of this. Kudos to Alexander, Alexey and the full CFP team!

Of course, we had to party ... joernchen set fire to the dance floor during the speakers' party (Hacker Hacker!) and the closing event was much more sociable, with plenty of interesting discussions. Visiting Moscow by night with some awesome hackers was clearly part of the fun ;-)

Regarding the non-XML talks ... The keynote by FX was truly inspiring, as promised. j00ru has rocked the Windows kernel, with a talk detailing the CPU / threads / RAM / ... costs for several CVE. The Finnish team (Miaubiz and Atte) did some feedback on their Chrome/Firefox fuzzing effort. Nice results! Nikita dropped on stage a win32k.sys 0-day found via binary diffing. As you can see, a lot of awesome content!!

Of course, I had a lot of expectations regarding the XML talks ... and I wasn't disappointed!

The OpenAM talk featured a FUSE driver based on two vulnerabilities (XXE + information leak) in the web interface. A YouTube video demonstrating the use of this driver ( is available here. Then, an application specific way to retrieve data using XXE and OOB channels and a Tomcat RCE via XXE and gopher:// were presented. They finished with a few slides on how to defend under Java (No, enabling FEATURE_SECURE_PROCESSING is not enough!).

The MongoDB talk was quite surprising: server-side execution of JavaScript code, nice BSON tricks used to overwrite or disclose raw data, ... The backend seems quite fragile and could be a nice target for a fuzzer. Unfortunately, the talk was in Russian and no translation was available. I probably missed a few interesting points.

Vladimir Voronstov aka d0znpp and Alexander Golovko spoke about new SSRF techniques. By the way, Oracle killed the gopher:// URL handler in a recent Java update :-( One of the fun aspects of SSRF is the fact that the HTTP client you use (curl, nanohttp, ...) is very different from your usual browser. Unsafe redirect from http:// to file://, support for exotic URL handlers like tftp:// and rtsp://, ... Plenty of cool features! Additionally, I would bet that the deployment of XInclude and XLink will offer a new and large attack surface during the next years. If you want to practice with SSRF, I recommend the ErsSma challenge published just before the conference.

My own talk was composed of three parts. First, beating XML blacklists with a few cheap tricks (UTF-8, whitespaces and namespaces manipulation, ...). Then, abusing XSLT features with exploitation of (among others) Postgres CVE-2012-3488 and Ektron CMS CVE-2012-5357. The section about fuzzing XSLT interpreters have generated some interest, with some funny bugs like the UTF-8 heap-overflow in Reader X (CVE-2012-1525). It was found using ASan on the open-source Sablotron engine. I received some good feedback and some very interesting questions. It's a pleasure to see people absorbing knowledge so quickly.

Now, some loosely organized links ...

XML at large :

"No locked doors, no windows barred: hacking OpenAM infrastructure"
Slides and Tools, by George Noseevich @webpentest and Andrew Petukhov @p3tand

"Attacking MongoDB"
Slides EN, Sides RU and Code, by Firstov Mihail @cyberpunkych

"SSRF attacks and sockets: smorgasbord of vulnerabilities"
Slides and SSRF Bible, by Vladimir Voronstov @d0znpp and Alexander Golovko

"That's why I love XML Hacking"
Prezi and PDF, by Nicolas Grégoire @Agarri_FR

Other talks:

"Win32/Flamer: Reverse Engineering and Framework Reconstruction"
Slides, by Aleksandr Matrosov @matrosov and Eugene Rodionov @vxradius

"New developments in password hashing: ROM-port-hard function"
Slides, by Alexander Peslyak @solardiz

"The art of binary diffing"
Slides, by Nikita Tarakanov @NTarakanov


"Random Numbers. Take Two"
Slides, by Arseny Reutov @ru_raz0r, Timur Yunusov and Dmitry Nagibin

"All you ever wanted to know about BeEF"
Slides, by Michele Orru @antisnatchor

"Reversing banking trojan: an in-depth look into Gataka"
Slides, by Jean-Ian Boutin @jiboutin

And many thanks to those who personally took care of myself during this trip and made it so enjoyable: Maria, Nikita, Dimitry, Alexey, ...

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