Geeky Shows: Cross-site request forgery, also known as a one-click attack or session riding and abbreviated as CSRF (sometimes pronounced sea-surf) or XSRF, is a type of malicious exploit of a website whereby unauthorized commands are transmitted from a user that the website trusts. Unlike cross-site scripting (XSS), which exploits the trust a user has for a particular site, CSRF exploits the trust that a site has in a user’s browser.
In a Cross Site Request Forgery attack, the attacker is exploiting how the target web application manages authentication. For CSRF to be exploited the victim must be authenticated against (logged in) to the target site. For instance let’s say examplebank.com has online banking that is vulnerable to CSRF. If I visit a page containing a CSRF attack on examplebank.com but am not currently logged in, nothing happens. I am logged in however, the requests in the attack will be executed as if they were actions that I had intended to do.