Bluetooth vulnerability enables hackers to mimic genuine devices

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Hackers could exploit newly discovered flaws in Bluetooth Core and Mesh Profile Specifications to disguise themselves as legitimate devices and carry out man-in-the-middle (MitM) attacks.

Researchers at the Agence nationale de la sécurité des systèmes d'information (ANSSI) have found flaws in the Bluetooth Core Specification and Mesh Profile Specification that allow impersonation attacks and AuthValue disclosures.

The two specifications define the technical and policy requirements for devices that want to operate over Bluetooth connections.

The Bluetooth Impersonation Attacks, or BIAS, allow attackers to impersonate a device and to establish a secure connection with a victim without possessing the long-term key shared by the impersonated device and the victim. This bypasses Bluetooth's authentication mechanism.

"The BIAS attacks are the first uncovering issues related to Bluetooth's secure connection establishment authentication procedures, adversarial role switches, and Secure Connections downgrades," the researchers said. "Our attacks are stealthy because the Bluetooth standard does not require to notify end users about the outcome of an authentication procedure, or the lack of mutual authentication."

"To confirm that the BIAS attacks are practical, we successfully conduct them against 31 Bluetooth devices (28 unique Bluetooth chips) from major hardware and software vendors, implementing all the major Bluetooth versions, including Apple, Qualcomm, Intel, Cypress, Broadcom, Samsung, and CSR."

Researchers added that the attacks work even when the victims use Bluetooth's strongest security modes, including SSP and Secure Connections.


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"Our attacks target the standardized Bluetooth authentication procedure and are therefore effective against any standard-compliant Bluetooth device," the researchers said.

According to a Carnegie Mellon CERT Coordination Center advisory, the Android Open-Source Project (AOSP), Cisco, Cradlepoint, Intel, Microchip Technology, and Red Hat are vendors affected by the security flaws.

The Bluetooth Special Interest Group (SIG), the organization that directs the development of Bluetooth standards, published a security notice about the flaws. It recommended potentially vulnerable implementations restrict the public keys accepted from a remote peer device to disallow a remote peer to present the same public key the local device chose.

"The Bluetooth SIG is also broadly communicating details on this vulnerability and its remedies to our member companies and is encouraging them to rapidly integrate any necessary patches. As always, Bluetooth users should ensure they have installed the latest recommended updates from device and operating system manufacturers," the organization said in a statement.

Rene Millman

Rene Millman is a freelance writer and broadcaster who covers cybersecurity, AI, IoT, and the cloud. He also works as a contributing analyst at GigaOm and has previously worked as an analyst for Gartner covering the infrastructure market. He has made numerous television appearances to give his views and expertise on technology trends and companies that affect and shape our lives. You can follow Rene Millman on Twitter.