What a Web Application Firewall Does
A Web Application Firewall (WAF) sits between your website and the internet. It inspects all incoming traffic, blocks malicious requests, and allows legitimate visitors through. Think of it as a security guard that checks every visitor before they enter your site.
Types of WAFs
Cloud-Based WAF: Sits on the CDN network and filters traffic before it reaches your server. Cloudflare and Sucuri offer cloud-based WAFs. Easiest to set up and most effective for most sites.
Plugin-Based WAF: Runs on your server as a WordPress plugin. Wordfence is the most popular. Good protection but adds server load.
Server-Level WAF: Configured at the server level. ModSecurity is the most common. Requires technical expertise to configure.
What a WAF Blocks
- SQL Injection: Malicious database queries through form fields
- Cross-Site Scripting (XSS): Malicious scripts injected into pages
- Brute Force Attacks: Automated login attempts
- DDoS Attacks: Distributed denial-of-service traffic floods
- Malicious Bots: Automated scrapers, scanners, and crawlers
- File Inclusion Attacks: Attempts to access unauthorized files
Cloudflare Free WAF
Cloudflare free tier includes basic WAF protection. It blocks common attacks and provides DDoS protection. Setup takes 15 minutes - change your nameservers to Cloudflare. For most small business websites, the free tier provides adequate protection.
Wordfence WAF
Wordfence includes a WAF that runs on your server. The free version provides real-time IP blocklist and basic firewall rules. Premium version adds real-time threat intelligence. Configure it to block known malicious IPs and patterns.
WAF Configuration Best Practices
- Enable WAF before doing anything else on a new site
- Configure it to block common attack patterns
- Monitor WAF logs for blocked attack attempts
- Whitelist legitimate IP addresses that may be误flagged
- Keep WAF rules updated
The Business Case for WAF
A single successful attack can cost ₹50,000-₹2,00,000 in cleanup, downtime, and lost business. A WAF costs ₹0-₹5,000 per year. The protection to cost ratio is overwhelmingly in favor of having a WAF. It is the most cost-effective security investment you can make.