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CLF-C02 Practice Question 6: Web Application Firewall

AWS Certified Cloud Practitioner (CLF-C02) · Test 1 · question 6 of 10

Security & Compliancemedium

Logs for a public web application running behind an Application Load Balancer show repeated SQL injection and cross-site scripting attempts in HTTP request parameters. Which AWS service should be used to inspect and block these malicious requests before they reach the application?

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Answer:

  • C. AWS WAF

AWS WAF is a web application firewall that inspects HTTP and HTTPS requests to CloudFront distributions, Application Load Balancers, API Gateway APIs, and other supported resources, and lets you allow, block, or count requests using rules, including AWS managed rule groups for common exploits such as SQL injection and cross-site scripting.

Option A, GuardDuty, is a threat detection service: it analyzes sources such as CloudTrail events, VPC flow logs, and DNS logs and raises findings, but it does not sit in the request path and cannot block a request. Option B, Shield Standard, is included at no additional charge and defends against common network and transport layer (layer 3 and 4) DDoS attacks; it does not filter application layer request content. Option D, network ACLs, filter traffic at the subnet boundary by IP address, protocol, and port, and have no visibility into the contents of an HTTP request.

Reference: What is AWS WAF?

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