Web application firewall (WAF)
A filter that inspects HTTP traffic and blocks malicious requests.
Security
Definition
A WAF sits in front of an application and applies rules to HTTP requests, blocking injection attempts, known exploit patterns and abusive automation.
Modern deployments combine managed rule sets with rate limiting and bot scoring.
Why it matters
Organic traffic is only valuable if the site stays available and uncompromised; a defacement or outage erases ranking gains quickly.
How to apply it
- Start in detection mode and tune before blocking.
- Rate-limit authentication and search endpoints.
- Alert on rule matches that correlate with traffic spikes.