Cross Site Request Forgery (XSRF)

In this type of attack unauthorized commands are sent from a user a website trusts. Consider an editor that is logged in to an application (like a CMS or online banking service) and therefore is authorized in the system. The authorization may be stored in a session cookie in the browser of the user. An attacker might send an e-mail to the person with a link that points to a website with prepared images. When the browser is loading the images, it might actually send a request to the system where the user is logged in and execute commands in the context of the logged-in user.

One way to prevent this type of attack is to include a secret token with every form or link that can be used to check the authentication of the request.