Chapter 3. Cross-Site Scripting

I believe XSS or cross-site scripting is the most popular web vulnerability, if not the most exploitable one. Almost every website had suffered in one or more ways from XSS. From social networking websites such as Facebook and MySpace to financial websites such as PayPal that handles thousands of dollars every day, everyone has had a run-in with XSS. XSS typically happens to be a user-supplied input (for example, text, details, messages, and so on), and it is either reflected by the page instantaneously, known as reflected XSS or when the user supplied inputs (such as messages, user profile details, and so on) that are saved into a database and then presented back on the page at a point in time and stored; the latter, known as stored XSS, happens when you enter your name, address, and so on, on a social networking website such as Facebook and these inputs are saved into Facebook's database to be displayed later when someone visits your profile...