AWS WAF (Web Application Firewall)

AWS WAF (Web Application Firewall) is a critical service for protecting web applications and APIs from common web exploits and attacks. It helps maintain application availability and security by monitoring HTTP/HTTPS requests and filtering out malicious traffic.

Importance of AWS WAF:
1. Protects against common web exploits like SQL injection, cross-site scripting (XSS), and other OWASP Top 10 security risks.
2. Helps maintain application availability by mitigating DDoS attacks and rate-limiting requests.
3. Provides customizable rules to allow or block specific traffic patterns.
4. Integrates with other AWS services like Amazon CloudFront, Application Load Balancer, and API Gateway for comprehensive protection.

How AWS WAF works:
1. Define customizable web security rules based on request signatures, IP addresses, query string parameters, and more.
2. Rules are grouped into a Web ACL (Access Control List) and associated with AWS resources.
3. Incoming requests are inspected by AWS WAF, and allowed or blocked based on the defined rules.
4. Blocked requests are logged for monitoring and analysis.

Exam Tips: Answering Questions on AWS WAF
1. Understand the use cases for AWS WAF, such as protecting against common web exploits and DDoS attacks.
2. Know the key components of AWS WAF, including Web ACLs, rules, and rule groups.
3. Be familiar with the AWS services that can integrate with AWS WAF, like Amazon CloudFront, Application Load Balancer, and API Gateway.
4. Recognize scenarios where AWS WAF can be used to filter traffic based on specific conditions, such as IP addresses, headers, or request patterns.
5. Differentiate between AWS WAF and other security services like AWS Shield and Amazon GuardDuty, and know when to use each service.