Welcome to Web Application Security For Dummies! Web applications have become the Achilles heel of IT security. Web application vulnerabilities are now the most prevalent at more than 55 percent of all server vulnerability disclosures. This figure doesn't include vulnerabilities in custom-developed web applications, so it may be just the tip of the iceberg. This book is all about understanding how to quickly find and fix vulnerabilities in web applications. The goal is to prevent attackers from gaining control over the application and obtaining easy access to the server, database, and other back-end IT resources.