Original Post: CSRF- Cross Site Request Forgery. CSRF attack is a web security… | by Omkarpotadar | Oct, 2024
The content explains Cross-Site Request Forgery (CSRF), a web security vulnerability where attackers trick authenticated users into performing unintended actions. CSRF bypasses the Same-Origin Policy (SOP) that prevents cross-site interference. Key points include:
-
How CSRF Works: An attacker crafts malicious sites that trigger requests to a user’s account when they are logged into a vulnerable application.
-
Common Vulnerabilities:
- Blindly trusting authenticated requests without verifying legitimacy.
- Absence of anti-CSRF protections like tokens.
- Inadequate validation of Referer/Origin headers.
- Insecure use of GET requests for state-changing actions.
- Automatic cookie sending in cross-origin requests.
-
Identifying Vulnerable Actions: Look for critical actions that change user data or involve sensitive transactions.
-
CSRF Protection Mechanisms:
- Use of Anti-CSRF tokens in forms or AJAX requests.
- Appropriate use of HTTP methods, ensuring state-changing actions are not performed with GET requests.
- Implementing the SameSite attribute for cookies.
-
Testing for CSRF: Simulate attacks using tools like Burp Suite to intercept requests, recreate them in HTML, and test whether actions can be performed without CSRF protections.
-
Defense Strategies: Check for referer or origin header validations to ensure requests come from valid sources. Test for bypass techniques on anti-CSRF tokens, ensuring they are neither reusable nor predictable.
- Prevention Measures:
- Implement anti-CSRF tokens to verify request sources.
- Use the SameSite cookie attribute.
- Validate Referer/Origin headers.
- Avoid state-changing actions with GET requests, opting for POST instead.
The content extensively outlines steps to identify, test, and protect against CSRF vulnerabilities in web applications.
Go here to read the Original Post