A vulnerability affecting Bluetooth BR/EDR pairing was found in the Bluetooth Core specification versions 1.0 through 5.2. The flaw could allow an attacking device to spoof the address of a previously paired remote device to successfully complete the authentication procedure with some paired/bonded devices while not possessing the link key. This can permit an attacker to initiate the Bluetooth Key Negotiation attack (KNOB) on encryption key strength without intervening in an ongoing pairing procedure through an injection attack.