See also: How to authenticate clients with the Multipass service,
authenticate,local.passphrase
A word of caution regarding security
Multipass is intended to be used for development and is not meant for production. As such, the project’s security scope is limited to development use and caution is advised if used in production.
Access to the Multipass daemon/service
Multipass runs a daemon that is accessed locally via a Unix socket on Linux and macOS and over a TLS socket on Windows. Anyone with access to the socket can fully control Multipass, which includes the ability to mount host file systems or to tweak the security features for all instances.
Therefore, make sure to restrict the access to the daemon to trusted users.
Local access to the Multipass daemon
The Multipass daemon runs as root and provides a Unix socket for local communication. Access control for Multipass is initially based on group membership and later by the client’s TLS certificate when accepted by providing a set passphrase.
The first client to connect that is a member of the sudo group (or wheel/adm depending on the OS) will automatically have its TLS certificate imported into the Multipass daemon and will be authenticated to connect. After this, any other client connecting will need to authenticate first by providing a passphrase set by the administrator.