Web Application Firewall Guide

A WAF protects web applications by filtering and monitoring HTTP traffic. It's a key defense against OWASP Top 10 vulnerabilities.

WAF Products

ModSecurity Rules

# Block SQL injection
SecRule ARGS "@rx (?i)(\b(select|insert|update|delete|drop)\b)" \
  "id:1001,phase:2,deny,status:403,msg:'SQL Injection Detected'"

# Block XSS
SecRule ARGS "@rx 

{
  "Name": "BlockSQLi",
  "Priority": 1,
  "Statement": {
    "SqliMatchStatement": {
      "FieldToMatch": { "AllQueryArguments": {} },
      "TextTransformations": [
        { "Priority": 0, "Type": "URL_DECODE" }
      ]
    }
  },
  "Action": { "Block": {} }
}