update the codeigniter script with security measures

We are already using active records, trim, $this->security->xss_clean, html_escape, strip_tags on the data being taken from input controls. However, we are looking to enhance the security and plug all other kinds of security vulnerabilities like file upload, csrf, etc. We need you to make sure that our scripts cannot be misused in any other manner and prevent the application / server from getting hacked through our PHP / Codeigniter scripts. Note: 1. Bid only if you can start the work immediately. 2. Bid only if you can support over anydesk/teamviewer