If you do not need VNC console access and want to maximize security, you can disable it by leaving the VNC password field blank in your server configuration.
With VNC disabled, the only way to access your server is through SSH (Linux) or RDP (Windows) over the network. This eliminates the console as a potential access point.
If you later need to re-enable VNC access, simply edit your server configuration and set a new VNC password. The change takes effect after a server restart.
For servers where you do use VNC, make sure to set a strong password and limit VNC use to initial setup or emergency recovery situations.