This is a Excellent Application on Learning PHP Security

This Course teaches you about the primary security considerations that can affect a PHP website, and how you can take preventative measures. Also helps you protect PHP-based websites that contain sensitive or financial information.

You will start by learning about the most common forms of attack and what the consequences can be when your website is not protected. You will then move into learning about the filtering and validation functions in PHP, and why you should use them. Doug will teach you how you can protect your website against common website vulnerabilities and how to protect file uploads. Finally, this video tutorial will teach you how to protect against SQL injection attacks, and covers topics such as database escaping, using prepared statements, and protecting a MySQL database.