"When it comes to security, remember that in addition to actual platform and operating system security issues, you need to ensure that you write your application to be secure. When you write PHP applications, apply these seven habits to make sure your applications are as secure as possible:
Validate input
Guard your file system
Guard your database
Guard your session data
Guard against Cross-Site Scripting (XSS) vulnerabilities
Verify form posts
Protect against Cross-Site Request Forgeries (CSRF)"
