Which vulnerability is characterized by performing unauthorized actions on a web application using an authenticated user’s credentials?

Which vulnerability is characterized by performing unauthorized actions on a web application using an authenticated user’s credentials?

• A. Cross-site request forgery (CSRF)
• B. Cross-site scripting (XSS)
• C. Broken authentication
• D. Directory traversal

Answer: (A)

Cross-site request forgery is at work when an attacker makes a user perform actions on a web application using that user’s authenticated session. The user is already logged in, so their browser sends the site's normal credentials (like a session cookie) with the forged request. The site sees a legitimate request from the user and carries out the action, even though the user didn’t intend to perform it. This leverages the trust a site has in the user’s authenticated session. This is different from cross-site scripting, which would inject and execute malicious code in the user’s browser, potentially stealing data or credentials. It’s also not about weaknesses in authentication itself (broken authentication) or about accessing files via directory traversal. CSRF specifically exploits the fact that actions are performed with the user’s existing credentials in an authenticated session. Mitigations include CSRF tokens, SameSite cookies, and requiring extra verification for sensitive actions.

Cross-site request forgery is at work when an attacker makes a user perform actions on a web application using that user’s authenticated session. The user is already logged in, so their browser sends the site's normal credentials (like a session cookie) with the forged request. The site sees a legitimate request from the user and carries out the action, even though the user didn’t intend to perform it. This leverages the trust a site has in the user’s authenticated session.

This is different from cross-site scripting, which would inject and execute malicious code in the user’s browser, potentially stealing data or credentials. It’s also not about weaknesses in authentication itself (broken authentication) or about accessing files via directory traversal. CSRF specifically exploits the fact that actions are performed with the user’s existing credentials in an authenticated session. Mitigations include CSRF tokens, SameSite cookies, and requiring extra verification for sensitive actions.