📖 What is AWS Web Application Firewall (WAF)?
AWS Web Application Firewall (WAF) is a web application firewall that helps protect web applications from common web exploits and bots. It allows you to create security rules that block common attack patterns, such as SQL injection or cross-site scripting (XSS).
"WAF operates at Layer 7 (Application Layer) and integrates directly with Application Load Balancers, Amazon CloudFront, and Amazon API Gateway."
📚 Certification: AWS Certified Solutions Architect - Associate (SAA-C03)
🔑 What are the Key Concepts of AWS Web Application Firewall (WAF)?
- ▸ Operates at Layer 7 (Application Layer) to inspect HTTP/HTTPS requests, allowing for granular filtering based on headers, query strings, and request bodies.
- ▸ Utilizes Managed Rule Groups from AWS or third parties to provide instant protection against common threats like the OWASP Top 10.
- ▸ Integrates seamlessly with Application Load Balancers, Amazon CloudFront, and Amazon API Gateway to secure the entry points of web applications.
- ▸ Supports custom rules for IP set blocking, geographic restrictions, and rate-limiting to prevent brute-force attacks or scrapers from overloading resources.
🎯 How does AWS Web Application Firewall (WAF) appear on the SAA-C03 Exam?
You may be asked to select the appropriate service to mitigate a Layer 7 DDoS attack or block specific SQL injection and cross-site scripting attempts targeting a public-facing web application.
A scenario might describe a requirement to block traffic from specific geographic regions or known malicious IP ranges before the traffic ever reaches the Application Load Balancer to ensure application stability.
Expect questions where you must differentiate between AWS WAF and AWS Shield; remember WAF handles application-level filtering, while Shield focuses on infrastructure-level DDoS protection at Layers 3 and 4.
❓ Frequently Asked Questions
How does AWS WAF differ from a Network ACL (NACL)?
NACLs operate at Layer 4 (Transport) and filter traffic based on IP and port. WAF operates at Layer 7 (Application) and can inspect the actual content of HTTP requests, such as headers and payloads, for malicious patterns.
Can AWS WAF be used with a Network Load Balancer (NLB)?
No, AWS WAF only integrates with Application Load Balancers, CloudFront, and API Gateway. For NLB protection, you must rely on Security Groups or AWS Shield for infrastructure-level protection, as NLBs do not inspect application-layer traffic.