No one interested in?
I will leave a couple of tips for who wants to play with it.
I've installed dropbear and
created a new key. I've tried to add my new public key to /.ssh/authorized_keys and /root/.ssh/authorized_keys but it doesn't work (dbclient still asks for root password, pubkey login doesn't work).
Maybe dropbear is configured to work just as a client? Why does it runs in background listening for open connections? It looks like a backdoor.