What is WAF (Web Application Firewall)?
Turkish: WAF
A WAF analyzes HTTP traffic at the application layer to filter SQL injection, XSS, malicious bots, and abusive requests.
What is a WAF?
A WAF (Web Application Firewall) is a security layer that inspects HTTP and HTTPS requests before they reach a web application. Its job is to catch known attack patterns, malicious bot behavior, and abnormal requests before application code processes them.
How It Works
A WAF is commonly placed at a reverse proxy, CDN edge, or load balancer. It evaluates signals such as the URL, headers, cookies, request body, IP reputation, and request rate against rule sets. The request can then be allowed, blocked, logged, or challenged with an extra control.
Rule sets often target OWASP risks, especially SQL injection and XSS attempts. A network firewall focuses on ports and IP traffic, while a WAF tries to understand HTTP content.
Risk and Protection
A WAF is an important layer for reducing hostile requests, but it does not replace secure coding, input validation, or authorization checks. Poorly tuned rules can block real users or leave critical endpoints insufficiently protected.
Business applications often use a WAF around checkout, login, admin panels, and API endpoints. Effective operation requires monitor mode, gradual enforcement, false-positive review, and regular rule updates.
Related Terms
A firewall filters traffic between devices and networks using rules, allowing approved connections while blocking suspicious or unauthorized access.
HoneypotA honeypot is an isolated decoy system, service, account, or data trap used to observe attacker behavior and generate early warnings.
OWASP (Open Web Application Security Project)OWASP is a nonprofit security organization that publishes resources like the OWASP Top 10 to improve web application security.