An issue in the Bluetooth Low Energy (BLE) control interface of the Yamaha SR-B30A sound bar firmware 2.40 (Mobile App: Sound Bar Remote / version: 2.40) allows remote attackers within BLE radio range to connect without authentication via the Sound Bar Remote protocol
https://gist.github.com/sohsatoh/02699fbbdff90e6c2078b508f830022b