--- title: Security --- # Security concerns Castopod is built on top of [CodeIgniter4](https://codeigniter.com/), a PHP framework that encourages [good security practices](https://codeigniter.com/user_guide/concepts/security.html). To maximize your instance's safety and prevent any malicious attack, we recommend you update all your Castopod files permissions after installation or updates (to avoid any prior permission error): - `writable/` folder must be **readable** and **writable**. - `public/media/` folder must be **readable** and **writable**. - any other file must be set to **readonly**. For instance, if you are using Apache or NGINX with Ubuntu you may do the following: ```bash sudo chown -R root:root /path/to/castopod sudo chown -R www-data:www-data /path/to/castopod/writable sudo chown -R www-data:www-data /path/to/castopod/public/media ```