hardware: bluetooth: BR/EDR encryption key negotiation attacks (KNOB)

A flaw was discovered in the Bluetooth protocol. An attacker within physical proximity to the Bluetooth connection could downgrade the encryption protocol to be trivially brute forced...

UBUNTU-CVE-2019-9506

The Bluetooth BR/EDR specification up to and including version 5.1 permits sufficiently low encryption key length and does not prevent an attacker from influencing the key length negotiation. This allows practical brute-force attacks aka "KNOB" that can decrypt traffic and inject arbitrary...