Glossary

What is a Web Application Firewall (WAF)?

February 8, 2026

A Web Application Firewall (WAF) sits between your website and the internet, filtering and blocking malicious HTTP traffic before it reaches your server. Unlike a traditional firewall that operates at the network level, a WAF understands web application protocols and can detect attacks targeting your WordPress site.

What a WAF Protects Against

  • SQL Injection — Attackers injecting malicious database queries.
  • Cross-Site Scripting (XSS) — Injecting malicious scripts into pages.
  • Brute force attacks — Repeated login attempts to guess passwords.
  • File inclusion attacks — Exploiting vulnerable plugins to include malicious files.
  • DDoS attacks — Flooding your server with traffic to take it offline.
  • Zero-day exploits — Virtual patching for newly discovered vulnerabilities.

Types of WAF

  • Cloud-based WAF — Runs on external servers (Cloudflare, Sucuri). Traffic is routed through the WAF before reaching your server. Easiest to set up.
  • Plugin-based WAF — Runs on your WordPress server (Wordfence). Inspects traffic at the application level.
  • Server-level WAF — Integrated into the web server (ModSecurity for Apache). Most efficient but requires server access.

Popular WordPress WAF Solutions

  • Cloudflare — Cloud WAF with free tier, includes CDN.
  • Wordfence — Most popular WordPress security plugin with built-in WAF.
  • Sucuri — Cloud-based WAF and CDN, malware scanning.
  • NinjaFirewall — Lightweight server-level WAF for WordPress.

What InspectWP Checks

InspectWP can detect some WAF solutions through response headers and DNS records, such as Cloudflare, Sucuri, or other cloud-based WAF providers.

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