VietMX Staff asked 3 years ago
Cross-site request forgeries (CSRF) are a class of attacks where unauthorized commands are transmitted to a website from a trusted user. Because they inherit the users cookies (and hence session information), they appear to be validly issued commands.
Consider:
<!-- Attempt to delete a user's account -->
<img src="https://accounts.mozilla.org/management/delete?confirm=true">When a user visits a page with that HTML fragment, the browser will attempt to make a GET request to that URL. If the user is logged in, the browser will provide their session cookies and the account deletion attempt will be successful.
The most common and transparent method of CSRF mitigation is through the use of anti-CSRF tokens. Anti-CSRF tokens prevent CSRF attacks by requiring the existence of a secret, unique, and unpredictable token on all destructive changes.
<!-- A secret anti-CSRF token, included in the form to delete an account -->
<input type="hidden" name="csrftoken" value="1df93e1eafa42012f9a8aff062eeb1db0380b">