Developer's Guide to Web Application Security

Introduction

As a programmer working on a Web application, you already know that if you want

your site to do something such as gather information through forms or customize

itself to your users, you will have to go beyond Hypertext Markup Language

(HTML).You will have to do Web programming, and the most common form used

today is Common Gateway Interface (CGI). CGI applies rules for running external

programs in a Web HTTP server. External programs are called gateways because they

open outside information to the server.

There are other ways to customize or add client activity to your Web site.You

could use JavaScript, which is a client-side scripting language. ...