Custom php,mysql application security development

Hi,

I have developed object oriented custom php/mysql portal application.

What are things to be done to implement security in application.

Please advise.

-Thanks

You can take a look at sanitizing all user input to protect against sql injection. Protecting against XSS and CSRF attacks are important too…check out this resource: https://www.owasp.org/index.php/PHP_Security_Cheat_Sheet