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AWS WAF
Protects supported AWS web endpoints with configurable inspection rules
Why learn AWS WAF?
Teams use AWS WAF to adopt web application firewall without building the complete underlying platform themselves.
The problem it solves
Filters malicious HTTP traffic using managed and custom security rules
Where it came from
AWS WAF is Amazon Web Services's offering for web application firewall. Its closest catalog counterparts are Azure Web Application Firewall and Google Cloud Armor; they address the same broad need but are not feature-for-feature identical.
Build your understanding
Work through these exercises in order. Try the task before opening a reference.
- Explain the main responsibility of AWS WAF.
- Choose a workload that fits AWS WAF.
- Identify one operational tradeoff of AWS WAF.
- Compare AWS WAF with Azure Web Application Firewall.
- Compare AWS WAF with Google Cloud Armor.
Documentation and sources
- AWS cloud services catalog (aws.amazon.com)
Connect the ideas
Alternatives
Real World Example
Securing Global E-Commerce Checkout Endpoints
A global e-commerce retailer operating a high-traffic checkout API that processes thousands of transactions per minute.
The business problem
The retailer faces frequent automated credential stuffing attacks and malicious bot traffic targeting their checkout endpoints, leading to unauthorized account access and increased infrastructure load.
How this topic solves it
AWS WAF provides a managed layer of defense by inspecting incoming web requests to supported AWS endpoints. By deploying configurable inspection rules, the retailer can filter out malicious traffic patterns, such as known bad IP addresses or abnormal request rates, before they reach the backend application servers.
- Define a Web ACL to serve as the central container for security rules.
- Configure managed rule groups to automatically block common web exploits and known bot signatures.
- Associate the Web ACL with the specific Amazon CloudFront distribution or Application Load Balancer hosting the checkout API.
- Monitor request patterns using WAF logs to refine rule sensitivity and minimize false positives.
This diagram illustrates the path of a web request through the AWS WAF inspection layer before reaching the application.
Inspection engine with Web ACL
Application Load Balancer
Checkout API Service
- Client → Sends HTTP Request → AWS WAF
- AWS WAF → Forwards allowed traffic → Endpoint
- Endpoint → Routes to API → Backend
Expected business outcome
The checkout service experiences a significant reduction in unauthorized traffic, ensuring that legitimate customer transactions are processed without interference from automated botnets.
Limitations and checks
A critical limitation is the potential for false positives where legitimate user traffic is blocked due to overly restrictive rules. Administrators must regularly review WAF logs to verify that legitimate traffic is not being inadvertently dropped.