XSS aka Cross Site Scripting is a client-side attack where an attacker can craft a malicious link, containing script- code which is then executed within the victim's browser when the target site vulnerable to and injected with XSS is viewed. The script-code can be any language supported by the browser but mostly HTML and Javascript is used along with embedded Flash, Java or ActiveX.

In some cases where the XSS vulnerability is persistent as described further below, the attacker will not have to craft a link as the injected script is inserted directly into the target site and / or web application. The target user(s) still has to view the affected site / page where the injected code is located though.

Source
http://pastebin.com/X35W0tkD

by
MaXe