bhyveload(8) host file access

bhyveload -h may be used to grant loader access to the directory tree on the host. Affected versions of bhyveload(8) do not make any attempt to restrict loader's access to , 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.