A Web Application Firewall (WAF) is a security control that filters, monitors, and blocks HTTP/HTTPS traffic between clients and web applications. WAF configuration involves defining rulesets, tuning detection thresholds, managing exceptions, and integrating with application development workflows to protect web applications from OWASP Top 10 attacks, API abuse, and automated threats without disrupting legitimate traffic.
WAFs inspect HTTP requests and responses against a set of rules designed to detect common web attacks. Core Rule Set (CRS) configurations from OWASP provide baseline protection against SQL injection, cross-site scripting, command injection, and path traversal. WAFs operate in detection or prevention mode. Initial deployment typically starts in detection mode to identify false positives before switching to prevention mode. Custom rules address application-specific attack vectors. Rate limiting rules throttle abusive request patterns. Bot management modules distinguish between legitimate bots, malicious scrapers, and credential stuffing tools. Positive security models define what valid requests look like and reject anything that deviates. IP reputation lists block known malicious sources. WAF configuration must be continuously tuned as applications evolve, with new rules added for new endpoints and exceptions refined as false positive patterns emerge.
Web applications are the primary attack surface for most organizations. Vulnerabilities in application code can be exploited before developers have time to patch them. WAFs provide a critical layer of protection that can block known attacks immediately while buying time for code remediation. They are particularly valuable for protecting legacy applications that cannot be easily updated and for meeting compliance requirements that mandate web application protection.
CDA addresses WAF configuration within the Vulnerability and Surface Defense domain. Our missions guide organizations through WAF deployment, rule tuning, false positive management, and integration with CI/CD pipelines. We validate WAF effectiveness through controlled attack testing that simulates real-world web exploitation techniques.