cisco-sa-20190813-bluetooth

Key Negotiation of Bluetooth Vulnerability

A weakness in the Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) protocol core specification exposes a vulnerability that could allow for an unauthenticated, adjacent attacker to perform a man-in-the-middle attack on an encrypted Bluetooth connection. The attack must be performed during negotiation or renegotiation of a paired device connection; existing sessions cannot be attacked. The issue could allow the attacker to reduce the entropy of the negotiated session key that is used to secure a Bluetooth connection between a paired device and a host device. An attacker who can successfully inject a malicious message into a Bluetooth connection during session negotiation or renegotiation could cause the strength of the session key to be susceptible to brute force attack. This advisory will be updated as additional information becomes available. There are no workarounds that address this vulnerability.