Nginx-UI arbitrary file write through the Import Certificate feature

Nginx-UI is a web interface to manage Nginx configurations. The Import Certificate feature allows arbitrary write into the system. The feature does not check if the provided user input is a certification/key and allows to write into arbitrary paths in the system. It's possible to leverage the vulnerability into a remote code execution overwriting the config file app.ini. Version 2.0.0.beta.12 fixed the issue.