The same way that all other 3rd party services do it: keep your systems up to date, do not expose unnecessary things to the outside, use strong passwords and SSH keys.
Vaultwarden also stores/syncs a local copy of your vault on each device. So if my home lab goes down or explodes or something, I can still sign into my cached copies then export and import onto a new instance
Been self hosting using vaultwarden for quite awhile now. Simply the best.
Love the idea and homelab in general, but that seems so damn scary!!! How do you be sure your shit is safe?
The same way that all other 3rd party services do it: keep your systems up to date, do not expose unnecessary things to the outside, use strong passwords and SSH keys.
Vaultwarden also stores/syncs a local copy of your vault on each device. So if my home lab goes down or explodes or something, I can still sign into my cached copies then export and import onto a new instance