Please note that this book was last updated in April 2012, even though the ISBN number and the publication date remain the same as for the first edition. 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 application security attacks, such as cross-site scripting, SQL injection, remote file inclusion, and others. Considering that most web sites today suffer from one problem or another, ModSecurity Handbook will help anyone who has a web site to run. The topics covered include: Installation and configuration of ModSecurityLogging of complete HTTP trafficRule writingIP address, session, and user trackingSession management hardeningWhitelisting, blacklisting, and IP reputation managementAdvanced blocking strategiesIntegration with other Apache modulesWorking with rule setsVirtual patchingPerformance considerationsContent injectionXML inspectionWriting rules in LuaExtending ModSecurity in CThe book is suitable for all reader levels: it contains step-by-step installation and configuration instructions for those just starting out, as well as detailed explanations of the internals and discussion of advanced techniques for seasoned users. A comprehensive reference manual is included in the second part of the book. Digital version of ModSecurity Handbook (PDF and EPUB) can be obtained directly from the author, at feistyduck.com.