Want to learn how to hack a website?
This tutorial -> http://jarlsberg.appspot.com/#0__hackers explains how to attack and defend against:
- Cross-Site Scripting (XSS)
 - Client-State Manipulation
 - Cross-Site Request Forgery (XSRF)
 - Cross Site Script Inclusion (XSSI)
 - Denial of Service
 - Code Execution
 - Configuration Vulnerabilities
 - AJAX vulnerabilities
 - Other Vulnerabilities (Buffer Overflow, Integer Overflow. SQL Injection)
 
