AWS WAF (Web Application Firewall)
AWS WAF is a web application firewall that monitors network requests that come into your web applications. It provides protection against common web exploits and attacks that could affect application availability, compromise security, or consume excessive resources.
How AWS WAF Works​
When a request comes into AWS WAF, it checks the request against a web access control list (web ACL) that you configure. The web ACL contains rules that define the traffic patterns to look for and the action to take when those patterns are found. If the request comes from a blocked IP address or matches malicious patterns, AWS WAF denies access. Legitimate requests are allowed through to your application.
Core Features​
Customizable Rules: Create custom rules to block or allow traffic based on IP addresses, HTTP headers, HTTP body, URI strings, SQL injection, and cross-site scripting (XSS) patterns.
Real-time Monitoring: Get real-time metrics and detailed logging of web requests, including the source of requests and which rules were triggered.
Easy Integration: Seamlessly integrates with Amazon CloudFront, Application Load Balancer, Amazon API Gateway, and AWS AppSync.
Managed Rule Groups: Use pre-configured rule sets maintained by AWS and AWS Marketplace sellers to protect against common threats.
Use Cases​
Protection Against Web Exploits​
Block common attack patterns such as SQL injection and cross-site scripting (XSS) attacks that could compromise your application's data or functionality.
Geographic Restrictions​
Restrict access to your application based on the geographic location of the request, helping you comply with local regulations or business requirements.
Rate Limiting​
Prevent abuse by limiting the number of requests from a single IP address within a specified time period, protecting against both automated attacks and excessive usage.
Bot Protection​
Identify and block malicious bots while allowing legitimate automated traffic like search engine crawlers to access your applications.
Connection to Other AWS Services​
Amazon CloudFront: Deploy WAF rules at CloudFront edge locations to filter malicious traffic closer to users and reduce latency for legitimate requests.
Application Load Balancer: Protect applications running on EC2 instances or containers by applying WAF rules at the load balancer level.
Amazon API Gateway: Secure your APIs by filtering requests before they reach your backend services, protecting against API-specific attacks.
AWS Shield: Works in conjunction with AWS Shield to provide comprehensive DDoS protection, with WAF handling application-layer attacks while Shield handles network-layer attacks.
AWS Lambda: Use Lambda functions to create custom responses to blocked requests or to implement complex filtering logic.
Benefits​
Cost-Effective Protection: Pay only for the web ACLs you create and the number of HTTP/HTTPS requests your applications receive.
Improved Performance: Filtering malicious traffic at the edge reduces the load on your origin servers, improving performance for legitimate users.
Simplified Management: Centralized rule management across all your web applications, with the ability to deploy rules globally.
Detailed Visibility: Comprehensive logging and monitoring help you understand attack patterns and fine-tune your security rules.
AWS WAF provides essential protection for web applications by filtering malicious traffic before it can reach your servers, helping you maintain application availability and security while gaining visibility into web-based threats.