What is WAF (Web Application Firewall) service?

A WAF (Web Application Firewall) service protects websites and apps by filtering, monitoring, and blocking malicious HTTP/HTTPS traffic, acting as a shield against common web attacks like SQL injection, Cross-Site Scripting (XSS), and bots, using custom rules, AI, and threat intelligence to identify and stop threats before they reach the application, with options including cloud, hardware, and software delivery models. 

What a WAF Service Does

• Monitors & Filters Traffic: Inspects incoming and outgoing HTTP/S traffic for malicious patterns, unlike traditional firewalls that focus on network layers.
• Blocks Attacks: Prevents common web exploits such as SQL injection, XSS, file inclusion, and malicious bot activity.
• Applies Policies: Uses customizable rules and policies to decide which traffic to allow or deny, based on application behavior and known threats.
• Provides Defense-in-Depth: Often part of a broader security strategy (WAAP) for comprehensive application security. 

Key Features & Benefits

• Threat Intelligence: Uses databases of known attack signatures and patterns.
• AI & Behavioral Analysis: Detects anomalies and new threats by learning normal application behavior.
• DDoS Mitigation: Integrates with DDoS protection to handle large-scale attacks, ensuring availability.
• Virtual Patching: Develops rapid defenses for newly discovered zero-day vulnerabilities.
• CDN Capabilities: Can cache content at the edge for faster load times. 

Types of WAFs

• Cloud-Based: Delivered as a service (WAF-as-a-Service), managed by the provider (e.g., AWS WAF, Cloudflare).
• Software-Based: Software installed on servers.
• Hardware-Based: Physical appliances deployed in front of servers. 

How it Works (Example)

1. Traffic Intercepted: All traffic to your web app goes through the WAF.
2. Inspection: The WAF analyzes HTTP requests (headers, body, URL).
3. Policy Check: Rules, signatures, and AI models check for malicious activity.
4. Action: Malicious requests are blocked; legitimate ones are passed to the server.