Apparently Raspbian does not yet have a fix for the BlueBorne vulnerability, which can be exploited by an attacker within range of the device, with no need for the attacker device to be paired to the target, or for the target to be discoverable.
Until patches are available, the only way to prevent this would be to disable the Bluetooth device altogether.
If I run
bluetoothctl and send it a
power off command, will that disable the BT adapter down deep enough to foil any such attack attempts?
(For clarification: just preventing malicious BT traffic from being processed is sufficient for my purposes—preventing BT from being accidentally re-enabled or similar, as suggested in the comments, is more than I need.)