Cross-site request forgery
Cross-site request forgery (CSRF) is an attack that tricks a user into making unwanted actions on a website, where they are already authenticated, while they are visiting another site. Say, in a forum, an attacker can place an IMG or IFRAME tag within the page that makes a carefully crafted request to the authenticated site.
For instance, the following fake 0x0 image can be embedded in a comment:
<img src="http://superbook.com/post?message=I+am+a+Dufus" width="0" height="0" border="0">If you have already signed into SuperBook from another tab, and if the site doesn't have CSRF countermeasures, then a very embarrassing message will be posted. In other words, CSRF allows the attacker to perform actions by assuming your identity.
How Django helps
The basic protection against CSRF is to use an HTTP POST (or PUT and DELETE, if supported) for any action that has side effects. Any GET (or HEAD) request must be used for information retrieval, for example, read-only...
