Cross-Site Request Forgery Cross-site request forgery, or CSRF, exploits the fact that a browser automatically sends existing session cookies to a site where the user is already logged in. The attacker does not need to know the password. It is enough to lead the user down the wrong path.

Cross-Site Scripting Cross-site scripting, better known as XSS, arises when a web application allows somebody else's script to be displayed and executed in the user's browser. The attacker does not have to break into the web server. It is enough for their code to end up in a page the victim opens as though it were entirely legitimate.