Snake bites : Python for Pentesters
A presentation at c0c0n 2013 in in Thiruvananthapuram, Kerala, India by Anant Shrivastava
Python for Web Pen-testers (Snake bites)
whoami Name : Anant Shrivastava work at 7Safe as a Information Security Consultant. Primary focus area’s include Web and mobile. Certifications : RHCE, CEH, SANS-GWAPT Speaker : Nullcon, ClubHack, c0c0n Creator of Android Tamer (a Virtual Machine for Android Security) Active member of null and Garage4Hackers open communities Website : http://anantshri.info Contact : anant@anantshri.info Twitter : @anantshri
Objectives ● ● ● Presentation is only focused on python. (No comparisons with other languages please) Idea is to introduce a regular web penetration tester with various functionalities available in Python and give them a head start There is no new tools release
Why Python ● ● ● Easy and Flexible Language Massive module base allowing lots of use case scenario’s to be written in small timeframe and codebase efforts. Inbuilt Language support in number of tools – Burp – IRONWASP ● API support provided by OWASP-ZAP ● Custom application logics or requirements ● Or as simple as JUST FOR THE FACT THAT YOU CAN DO IT
Example of Existing Python Tools w3af Canvas SpikeProxy Pyscan sqlmap DeBlaze ProxyStrike Scapy wapiti MonkeyFist sulley Pcapy Peach MyNav Idapython
Python Variations ● Cython ● Jython ● IronPython Remember to consider these two as different ● Python 2.X ● Python 3.X
Noteworthy Python modules
Python Modules ● Python has a set of inbuild packages listed as http://docs.python.org/2/library/index.html (2.7.3) ● Besides these packages community has provided a large set of modules and this is what
Standard Modules
External Modules
Requests ● Module alternative for urllib2 (HTTP handler) ● Internally handles the http or https transition. ● Simpler interface exposed ● Sample PoC import requests r = requests.get (get being one of the http method) r.text/r.content = content r.status_code r.headers Read more here : http://docs.python-requests.org/en/latest/user/quickstart/
BeautifulSoup ● Text / HTML parser Sample (I am using standard parser works fine so far but people recommend using a different parser) ● – import request – from BeautifulSoup import BeautifulSoup – r=requests.get(‘http://www.anantshri.info’) – soup=BeautifulSoup(r.text) – //searches for each div with class attachment – each_div=soup.find(‘div’,{‘class’:’attachment’}) Demo : Wordpress attachment enumeration
Argparse Create a quick and simple program with various options and switches Import argparse desc=”“”Description goes here”“” parser = argparse.ArgumentParser(description=desc) parser.add_argument(“—url”,help=”URL”,dest=’target’,required= True) parser.add_argument(“—debug”,help=”debug”,action=”store_tru e”) x=parser.parse_args() x.target == url x.debug == debug
Demo ● Scenario’s – Regular expression pattern matching – XSS Fuzzing / parameter fuzzing – SVN files extraction (.svn publically exposed)
Regular Expression Pattern Match #!/usr/bin/python import requests import re regex_array = { ‘wordpress’ : ‘<link rel=”stylesheet” [^>]+wp-content’, ‘Drupal’ : ‘<(?:link|style)[^>]+sites/(?:default|all)/(?:themes|modules)/’} r=requests.get(‘http://www.anantshri.com’) for k, v in regex_array.iteritems(): m=re.search(v,r.content) if (m): print k, ” : Detected ” , ” as the content has : “, m.group(0)
Simple XSS Fuzzer #!/usr/bin/python import requests import sys import argparse import os import urllib url=”http://fuzz/noxss.php?a=” f=open(‘xss.txt’,’r’) for row in f.readlines(): r = requests.get(url + urllib.quote(row)) if (row in r.content): print row
SVN extractor https://github.com/anantshri/svn-extractor simple script to extract all web resources by means of .SVN folder exposed over network. http://blog.anantshri.info/svn-extractor-for-web-pentesters
More Stuff ● http://learnpythonthehardway.org/book/ ● http://www.diveintopython.net/toc/index.html ● Go for SPSE or any on-line certification Course ● Read Violent Python ● Read Grey-hat Python ● Use Python on a daily basis for all operations. ● Use inbuilt support / features in – IRONWASP (In-line scripting) – BURP (Extension)
References for slides ● ● ● Large number of google searches and head scratching on various stackoverflow post’s. Awesome documentations at docs.python.org Direct interaction with super helpful guys from null specially Akash Mahajan, Lava Kumar, Prasanna and Amol Naik for helping, criticizing forcing me to improve the skill set.
Thank You If you wish to contact me after this presentation please use anant@anantshri.info For communication
PyInstaller ● ● Sometimes you want to shift your code as a one click executable without python dependency. PyInstaller packages every dependency into a single executable package http://www.pyinstaller.org/
Python for Android ● ● ● ● Python 2.7 installable on android Can use android specific features with the help of SL4A (scripting language for android) Ssh or laptop are not the restrictions now. Sample scripts refer here : http://code.google.com/p/python-for-android/wiki/
Thank You
A beginner level presentation made for c0c0n 2013 to talk about some basic modules of python which can be used in routine penetration testing exercises.
