LightBulb is an open source python framework for auditing web application firewalls and filters.

Synopsis
The framework consists of two main algorithms:

• GOFA: An active learning algorithm that infers symbolic representations of automata in the standard membership/equivalence query model.
  Active learning algorithms permits the analysis of filter and sanitizer programs remotely, i.e. given only the ability to query the targeted program and observe the output.
  
• SFADiff: A black-box differential testing algorithm based on Symbolic Finite Automata (SFA) learning
  Finding differences between programs with similar functionality is an important security problem as such differences can be used for fingerprinting or creating evasion attacks against security software like Web Application Firewalls (WAFs) which are designed to detect malicious inputs to web applications.

Motivation
Web Applications Firewalls (WAFs) are fundamental building blocks of modern application security. For example, the PCI standard for organizations handling credit card transactions dictates that any application facing the internet should be either protected by a WAF or successfully pass a code review process. Nevertheless, despite their popularity and importance, auditing web application firewalls remains a challenging and complex task. Finding attacks that bypass the firewall usually requires expert domain knowledge for a specific vulnerability class. Thus, penetration testers not armed with this knowledge are left with publicly available lists of attack strings, like the XSS Cheat Sheet, which are usually insufficient for thoroughly evaluating the security of a WAF product.

Commands Usage
Main interface commands:

Command	Description
core	Shows available core modules
utils	Shows available query handlers
info <module>	Prints module information
library	Enters library
modules	Shows available application modules
use <module>	Enters module
start <moduleA> <moduleB>	Initiate algorithm
help	Prints help
status	Checks and installs required packages
complete	Prints bash completion command

Module commands:

Command	Description
back	Go back to main menu
info	Prints current module information
library	Enters library
options	Shows available options
define <option> <value>	Set an option value
start	Initiate algoritm
complete	Prints bash completion command

Library commands:

Command	Description
back	Go back to main menu
info <folder\module>	Prints requested module information (folder must be located in lightbulb/data/)
cat <folder\module>	Prints requested module (folder must be located in lightbulb/data/)
modules <folder>	Shows available library modules in the requested folder (folder must be located in lightbulb/data/)
search <keywords>	Searches available library modules using comma separated keywords
complete	Prints bash completion command

Installation

Prepare your system
First you have to verify that your system supports flex, python dev, pip and build utilities:
For apt platforms (ubuntu, debian...):
(Optional for apt) If you want to add support for MySQL testing:
For yum platforms (centos, redhat, fedora...) with already installed the extra packages repo (epel-release):
(Optional for yum) If you want to add support for MySQL testing:

Install Lightbulb
In order to use the application without complete package installation:
In order to perform complete package installation. You can also install it from pip repository. This requires first to install the latest setuptools version:
If you want to use virtualenv:
The "lightbulb status" command will guide you to install MySQLdb and OpenFst support. If you use virtualenv in linux, the "sudo" command will be required only for the installation of libmysqlclient-dev package.
It should be noted that the "lightbulb status" command is not necessary if you are going to use the Burp Extension. The reason is that this command installs the "openfst" and "mysql" bindings and the extension by default is using Jython, which does not support C bindings. It is recommended to use the command only if you want to change the Burp extension configuration from the settings and enable the native support.
It is also possible to use a docker instance:


Install Burp Extension
If you wish to use the new GUI, you can use the extension for the Burp Suite. First you have to setup a working environment with Burp Proxy and Jython

• Download the latest Jython from here
• Find your local python packages installation folder*
• Configure Burp Extender to use these values, as shown below*

• Select the new LightBulb module ("BurpExtension.py") and set the extension type to be "Python"

*You can ignore this step, and install the standalone version which contains all the required python packages included. You can download it here

Examples
Check out the Wiki page for usage examples.

Contributors

• George Argyros
• Ioannis Stais
• Suman Jana
• Angelos D. Keromytis
• Aggelos Kiayias

References

• G. Argyros, I. Stais, S. Jana, A. D. Keromytis, and A. Kiayias. 2016. SFADiff: Automated Evasion Attacks and Fingerprinting Using Black-box Differential Automata Learning. In Proceedings of the 2016 ACM SIGSAC Conference on Computer and Communications Security (CCS '16). ACM, New York, NY, USA, 1690-1701. doi: 10.1145/2976749.2978383
• G. Argyros, I. Stais, A. Kiayias and A. D. Keromytis, "Back in Black: Towards Formal, Black Box Analysis of Sanitizers and Filters," 2016 IEEE Symposium on Security and Privacy (SP), San Jose, CA, 2016, pp. 91-109. doi: 10.1109/SP.2016.14