Add authentication to VNC?

[link]

I've recently set up EveNG in our lab environment and its working well. However, it appears our SIEM team have detected that there are VNC servers listening with no authentication required. As such, I'd like to add a simple auth mechanism in front of the VNC's. Even just requiring a password would be sufficient.

Is that something thats possible to do? I've not seen anything in the documentation, but would be happy to be corrected if I've missed it.

Edit- on a re-read, I realise the above is not all that clear. To clarify: I am referring to nodes with VNC as the console type. As long as that node is online, there will be an open port that will accept a VNC connection without any authentication required (Obviously the node it connects to may then require auth, but the VNC connection itself is open). The SIEM team are then detecting these nodes as an 'open' VNC and flagging them.

[link]

Thanks for the reply. I think adding individual individual passwords on the lab yaml will work for my case, however I'm not sure where thats located. I can find a .uml files in /opt/unetlab/labs which appear to contain XML, but the only yml files I see are the templates for the node types (Which I don't think is what you are talking about?) I'm using the community version if that makes a difference?