You're a cybersecurity analyst tasked with understanding the functionality of a Web Application Firewall (WAF) and its role in protecting web applications from various attacks. You need to grasp the benefits and limitations of WAFs and learn how to analyze log files generated by WAF tools like ModSecurity to detect web-based attacks.
What is the primary function of a Web Application Firewall (WAF)?
Correct Answer: A
According to the CHFI v11 Web Application Forensics and WAF module, the primary function of a Web Application Firewall (WAF) is to inspect, monitor, and filter HTTP/HTTPS traffic between a web application and its users. Unlike traditional network firewalls, which operate at the network or transport layer, WAFs function at the application layer (Layer 7) and are specifically designed to protect web applications from attacks such as SQL injection, Cross-Site Scripting (XSS), command injection, file inclusion, parameter tampering, and cookie poisoning.
WAFs such as ModSecurity analyze web requests and responses using rule-based logic, signatures, anomaly detection, and behavioral analysis. CHFI v11 emphasizes that WAF logs are critical forensic artifacts, as they record blocked requests, rule violations, payload details, source IP addresses, timestamps, and attack patterns. These logs allow investigators to detect, reconstruct, and attribute web-based attacks during forensic investigations.