ModSecurity Handbook is the definitive guide to ModSecurity, a popular open source web application firewall. Written by Ivan Ristic, who designed and wrote much of ModSecurity, this book will teach you everything you need to know to monitor the activity on your web sites and protect them from attack. Situated between your web sites and the world, web application firewalls provide an additional security layer, monitoring everything that comes in and everything that goes out. They enable you to perform many advanced activities, such as real-time application security monitoring, access control, virtual patching, HTTP traffic logging, continuous passive security assessment, and web application hardening. They can be very effective in preventing applicat...