John works as a professional Ethical Hacker. He has been assigned a project to test the security and successfully logs in to the user page of the Web site. The We-are-secure login page is vulnerable…

A replay attack involves intercepting and reusing valid session tokens or credentials, not actively bypassing authentication through input manipulation.

A land attack is a network-layer denial-of-service technique that sends packets with the same source and destination IP, and has no relevance to web application login page vulnerabilities.

SQL injection on a login page works by inserting SQL syntax such as ' OR '1'='1 into username or password fields, which manipulates the underlying SQL query so it always returns true and grants access without valid credentials. This attack targets the failure to properly parameterize or sanitize user input before it is passed to the database engine, allowing the attacker to subvert authentication logic entirely.

A dictionary attack involves brute-forcing credentials using a wordlist of common passwords, which requires valid credentials to exist and does not exploit query logic flaws.