Bluetooth BR/EDR devices with Secure Simple Pairing and Secure Connections pairing in Bluetooth Core Specification 4.2 through 5.4 allow certain man-in-the-middle attacks that force a short key length, and might lead to discovery of the encryption key and live injection, aka BLUFFS.

Bluetooth Classic in Bluetooth Core Specification through 5.3 does not properly conceal device information for Bluetooth transceivers in Non-Discoverable mode. By conducting an efficient over-the-air attack, an attacker can fully extract the permanent, unique Bluetooth MAC identifier, along with device capabilities and identifiers, some of which may contain identifying information about the device owner. This additionally allows the attacker to establish a connection to the target device.

Bluetooth® Pairing in Bluetooth Core Specification v1.0B through v5.3 may permit an unauthenticated MITM to acquire credentials with two pairing devices via adjacent access when at least one device supports BR/EDR Secure Connections pairing and the other BR/EDR Legacy PIN code pairing if the MITM negotiates BR/EDR Secure Simple Pairing in Secure Connections mode using the Passkey association model with the pairing Initiator and BR/EDR Legacy PIN code pairing with the pairing Responder and brute forces the Passkey entered by the user into the Responder as a 6-digit PIN code. The MITM attacker can use the identified PIN code value as the Passkey value to complete authentication with the Initiator via Bluetooth pairing method confusion.

Bluetooth® Low Energy Pairing in Bluetooth Core Specification v4.0 through v5.3 may permit an unauthenticated MITM to acquire credentials with two pairing devices via adjacent access when the MITM negotiates Legacy Passkey Pairing with the pairing Initiator and Secure Connections Passkey Pairing with the pairing Responder and brute forces the Passkey entered by the user into the Initiator. The MITM attacker can use the identified Passkey value to complete authentication with the Responder via Bluetooth pairing method confusion.