The main aim of XSS is to execute JavaScript on the victim's browser but there are different ways to achieve it, depending on the design and purpose of the website. There are three major categories of XSS:
Persistent XSS
Reflected XSS
DOM XSS
This form of cross-site scripting is also known as stored XSS. A XSS flaw is called a persistent XSS when the injected data is stored on the webserver or the database on the server side and the application serves it back to the user without validation. An attacker whose aim is to infect every visitor of the website would use the persistent XSS attack, which would enable him or her to exploit the website on a large scale.
Typical targets of persistent XSS flaws are as follows:
Web-based discussion forums
Social networking websites
News websites
Persistent XSS is considered to be more serious than other XSS flaws, as the attacker's malicious script is injected in the victim's browser automatically. This does not require...