New Bluetooth security flaw discovered; limited risk on iOS devices

A new Bluetooth security flaw has been discovered that would potentially allow an attacker to connect to a user device without authentication.

The Bluetooth Special Interest Group (SIG), the body responsible for Bluetooth standards, has confirmed vulnerabilities separately discovered by two teams of security researchers…

Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) and Purdue University have independently identified vulnerabilities related to Cross-Transport Key Derivation (CTKD) in implementations supporting pairing and encryption with both Bluetooth BR/EDR and LE in Bluetooth Specifications 4.0 through 5.0 […]

For this attack to be successful, an attacking device would need to be within wireless range of a vulnerable Bluetooth device supporting both BR/EDR and LE transports that supports CTKD between the transports and permits pairing on either the BR/EDR or LE transport either with no authentication (e.g. JustWorks) or no user-controlled access restrictions on the availability of pairing. If a device spoofing another device’s identity becomes paired or bonded on a transport and CTKD is used to derive a key which then overwrites a pre-existing key of greater strength or that was created using authentication, then access to authenticated services may occur. This may permit a Man In The Middle (MITM) attack between devices previously bonded using authenticated pairing when those peer devices are both vulnerable.