This book is a practical guide to discovering and exploiting security flaws in web applications. By “web applications” we mean those that are accessed using a web browser to communicate with a web server. We examine a wide variety of different technologies, such as databases, file systems, and web services, but only in the context in which these are employed by web applications.
If you want to learn how to run port scans, attack firewalls, or break into servers in other ways, we suggest you look elsewhere. But if you want to know how to hack into a web application, steal sensitive data, and perform unauthorized actions, this is the book for you. There is enough that is interesting and fun to say on that subject without straying into any other territory.