Bluetooth firmware or operating system software drivers in macOS versions before 10.13, High Sierra and iOS versions before 11.4, and Android versions before the 2018-06-05 patch may not sufficiently validate elliptic curve parameters used to generate public keys during a Diffie-Hellman key exchange, which may allow a remote attacker to obtain the encryption key used by the device.
https://www.kb.cert.org/vuls/id/304725
https://www.bluetooth.com/news/unknown/2018/07/bluetooth-sig-security-update
https://usn.ubuntu.com/4351-1/
https://usn.ubuntu.com/4118-1/
https://usn.ubuntu.com/4095-2/
https://usn.ubuntu.com/4095-1/
https://usn.ubuntu.com/4094-1/
https://lists.debian.org/debian-lts-announce/2019/04/msg00005.html
https://access.redhat.com/errata/RHSA-2019:2169
http://www.securitytracker.com/id/1041432