CompTIA Security+ Question D-5

The BEST methods for a web developer to prevent the website application code from being vulnerable to cross-site request forgery (XSRF) are to: (Select TWO).

A. Permit redirection to Internet-facing web URLs.
B. Ensure all HTML tags are enclosed in angle brackets, e.g., ”<” and “>”.
C. Validate and filter input on the server side and client side.
D. Use a web proxy to pass website requests between the user and the application.
E. Restrict and sanitize use of special characters in input and URLs.

Answer: C,E

XSRF or cross-site request forgery applies to web applications and is an attack that exploits the web application’s trust of a user who known or is supposed to have been authenticated. This is often accomplished without the user’s knowledge. XSRF can be prevented by adding a randomization string (called a nonce) to each URL request and session establishment and checking the client HTTP request header referrer for spoofing.