Bypassing Modern WAF's Exemplified At XSS (Webcast)

Past Saturday, I conducted a "Webcast" on "Garage4hackers" on one of my favorite subjects in the field of Information Security i.e. "WAF Bypass". Initially, i had decided to present something on the topic of "Mobile Browser Security" due to the fact that this has been a topic I have been recently conducting a research on.

However i later realized that the "TakeAways" would not be much helpful, therefore i decided to talk about something that Bughunters/Pentesters can use in their day to day pentests and security engagements and hence i decided to present on this topic.

I must admit that the response has been overwhelming along with it, i have also managed to get a chance to learn more from the feedback and CTF responses.

I would like to specially thank "Imdadullah", "Himanshu", "Sandeep"  along with other garage4hackers members for inviting/supporting me through out the journey.  One of the best things "G4H Community" is the work they are doing for the security community by conducting free of cost Webcasts. You can find a list of other Webcasts here - "http://www.garage4hackers.com/ranchoddas/"

Abstract

It is known that over the years, a trend that addresses the information security landscape has emerged, I mean, web applications are under attack, given this perspective, Web Application Firewalls are becoming increasingly popular, which are most commonly used by organizations to protect against various attacks such as SQL Injection, XSS etc.

While WAF's may help preventing application layer attacks up to some extent, however they certainly are not replacements for input validation and secure coding practices due to the fact that they are based upon Blacklists which means rejection of known patterns while allowing everything else. The problem, especially in case of JavaScript is that it's simply not possible to create blacklists capable of blocking all patterns without having to generate false positives due to the dynamic nature of javaScript and infinite ways of obfuscating the payload.

In this webinar, the we will talk about various techniques that can be used to bypass WAF"s such as Brute Forcing, Regular expression reversing and browser bugs. The webinar would mostly discuss

Prerequisite

- Basic knowledge about HTML/JavaScript

- Basic know how about XSS attacks

Webcast 


 

CTF Competition

After the webinar, we had this "CTF" challenge made up by a friend of mine "FileDescriptor", certain parts the first two challenges are based upon characteristics of a real world WAF that I encountered in wild which was combined with FD's ideas to make up the challenge . The last challenge is based upon "@FileDescriptor" unqiue idea and hence, it's not easy to crack and hence we named it as "Hard".

CTF Link :http://92.222.71.224

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by Malik korrich ~ mardi 3 mai 2016 0 commentaires

Web Application Firewall Detection – Kali Linux Tutorial

WAF or Web application firewall is a security tool that protects a website from various type of attacks which included but not limited to: SQL-injection, XSS, Local file inclusion and others. Web based IPS (intrusion prevention system) has also been designed to protect a web server but these is a difference between WAF and IPS; web application firewall provides protection from web-based attack while IPS protect a web server from network based attack.

The responsibility of a penetration tester is to protect the web server from both directional attacks, so IPS and WAF are both have their own importance for a pen tester. In order to conduct a successful vulnerability assessment on a website, you need to find the security tools that are protecting it.

WAFW00F is the tool to find a web application firewall that is protecting a web server. WAFW00f is a python script which is written by Sandro Gauci && Wendel G. Henrique. A penetration tester can get name of the installed firewall so that exploitation will be started, it was earlier available on backtrack 5 but since backtrack is no longer an active project; so we can use this tool on Kali Linux.

Application → Kali Linux → Information Gathering → IDS/IPS Identification → wafw00f

        _   __  _   ____ _   __  _    _   ____
       ///7/ /.' \ / __////7/ /,' \ ,' \ / __/
      | V V // o // _/ | V V // 0 // 0 // _/ 
      |_n_,'/_n_//_/   |_n_,' \_,' \_,'/_/   
                                <  
                                 ...'
                                
    WAFW00F - Web Application Firewall Detection Tool
   
    By Sandro Gauci && Wendel G. Henrique

Usage: wafw00f url1 [url2 [url3 ... ]]
example: wafw00f http://www.victim.org/

Options:
  -h, --help            show this help message and exit
  -v, --verbose         enable verbosity - multiple -v options increase
                        verbosity
  -a, --findall         Find all WAFs, do not stop testing on the first one
  -r, --disableredirect
                        Do not follow redirections given by 3xx responses
  -t TEST, --test=TEST  Test for one specific WAF
  -l, --list            List all WAFs that we are able to detect
  --xmlrpc              Switch on the XML-RPC interface instead of CUI
  --xmlrpcport=XMLRPCPORT
                        Specify an alternative port to listen on, default 8001
  -V, --version         Print out the version

Everything has its limitation, wafw00f has also some limitation. It can only detect the firewalls which are listed in the script database, so it is recommended that you should update your tool. In the following example you can see that the firewall name was not fetched by wafw00f.

Note: If you want to learn more about Linux and Windows based Penetration testing, you might want to subscribe our RSS feed and Email Subscription  or become our Facebook fan! You will get all the latest updates at both the places.

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by Malik korrich ~ mercredi 4 décembre 2013 0 commentaires