Which of the following common security vulnerabilities can be mitigated by using put validation?

A brute-force attack involves systematically trying many passwords and is mitigated by account lockout policies or multi-factor authentication, not input validation.

Cross-site scripting (XSS) is mitigated by output encoding to prevent malicious scripts from executing in a user's browser, not primarily by input validation (though input validation is still good practice).

Input validation directly mitigates SQL injection by ensuring that any data submitted by a user does not contain malicious SQL commands, thereby preventing them from being executed on the database.

Cross-site request forgery (CSRF) is mitigated by using anti-CSRF tokens to ensure requests originate from the legitimate web application, not by input validation.