`bhyveload -h <host-path>` may be used to grant loader access to the <host-path> directory tree on the host.  Affected versions of bhyveload(8) do not make any attempt to restrict loader's access to <host-path>, allowing the loader to read any file the host user has access to. In the bhyveload(8) model, the host supplies a userboot.so to boot with, but the loader scripts generally come from the guest image.  A maliciously crafted script could be used to exfiltrate sensitive data from the host accessible to the user running bhyhveload(8), which is often the system root.

FreeBSD https://security.freebsd.org/advisories/FreeBSD-SA-24:01.bhyveload.asc [No types assigned]