Which device uses specific rule sets to prevent common web application attacks such as cross-site scripting and SQL injection?

Which device uses specific rule sets to prevent common web application attacks such as cross-site scripting and SQL injection?

• A. Web Application Firewall (WAF)
• B. Proxy Server
• C. NAT Gateway
• D. API Gateway

Answer: (A)

Web Application Firewalls protect web applications by inspecting HTTP/S traffic and enforcing a rule set that detects and blocks malicious input. They’re designed to recognize patterns used in common attacks like cross-site scripting and SQL injection and to stop those requests before they reach the application. This focused, rule-driven protection at the application layer is what makes a WAF the best choice. Other devices operate at different layers or scopes: a proxy server may filter traffic but isn’t specialized to guard against web app payload attacks; a NAT gateway handles address translation and doesn’t inspect application content; an API gateway manages API access and security but isn’t specifically built to defend traditional web applications from XSS or SQL injection.