The Bluetooth Classic implementation in the Zhuhai Jieli AC6366C BT SDK through 0.9.1 does not properly handle the reception of truncated LMP_SCO_Link_Request packets while no other BT connections are active, allowing attackers in radio range to prevent new BT connections (disabling the AB5301A inquiry and page scan procedures) via a crafted LMP packet. The user needs to manually perform a power cycle (restart) of the device to restore BT connectivity.