Cross-Site Request Forgery (CSRF): An Overview and Mitigation Techniques

 CSRF (Cross-Site Request Forgery)

Cross-site request Forgery (CSRF) is a type of security attack in which an attacker tricks a user into performing actions on a web application without their consent. This is done by exploiting a web application's trust in the user’s browser.

Here’s how a CSRF attack typically works:

• Victim Authentication: The victim logs into a web application, and the browser stores a session cookie to authenticate the identity.
• Malicious Request: The attacker crafts a malicious request to the web application and embeds it in a link or form on a different website.
• User Interaction: The victim unknowingly interacts with the malicious link or form, which sends the crafted request to the web application.
• Execution: The web application processes the request as if it were a legitimate action from the authenticated user because it includes the user’s session cookie.

Example Scenario

Imagine a banking website where users can transfer money. If an attacker sends a link to the victim that, when clicked, requests to transfer money from the victim’s account to the attacker’s account, the banking website will process this request because it appears to come from the authenticated user.

Mitigation Strategies

To protect against CSRF attacks, web developers can implement several strategies:

• CSRF Tokens: Include a unique token in each form submission that the server can validate.
• SameSite Cookies: Use the SameSite attribute in cookies to prevent them from being sent with cross-site requests.
• Referer Header Validation: Check the Referer header to ensure requests come from trusted sources.

CSRF attacks can be quite dangerous, but with proper security measures, they can be effectively mitigated.

This is covered in CySA+, Pentest+, and Security+.