This guide attempts to provide a comprehensive overview of web application security. Common web application security issues and methods how to prevent them are explained. Web server and operating system security are not covered. The guide is intended mainly for web application developers, but can also provide useful information for web application reviewers.
The checklist gives a short summary containing only the individual guidelines. It is recommended to take the time and read the full version, where the guidelines are explained in detail, especially if any questions arise.
Most web application developers probably (hopefully) already know some or even most of the points mentioned in this guide. However, there will probably be something new for every developer. Remember, as a developer it is your responsibility to develop your application securely, and a single mistake may be enough to allow an attack.