The ctl_write_buffer and ctl_read_buffer functions allocated memory to be returned to userspace, without initializing it.

Malicious software running in a guest VM that exposes virtio_scsi can exploit the vulnerabilities to achieve code execution on the host in the bhyve userspace process, which typically runs as root. Note that bhyve runs in a Capsicum sandbox, so malicious code is constrained by the capabilities available to the bhyve process. A malicious iSCSI initiator could achieve remote code execution on the iSCSI target host.