Biblio

Bluetooth (BR/EDR) is a pervasive technology for wireless communication used by billions of devices. The Bluetooth standard includes a legacy authentication procedure and a secure authentication procedure, allowing devices to authenticate to each other using a long term key. Those procedures are used during pairing and secure connection establishment to prevent impersonation attacks. In this paper, we show that the Bluetooth specification contains vulnerabilities enabling to perform impersonation attacks during secure connection establishment. Such vulnerabilities include the lack of mandatory mutual authentication, overly permissive role switching, and an authentication procedure downgrade. We describe each vulnerability in detail, and we exploit them to design, implement, and evaluate master and slave impersonation attacks on both the legacy authentication procedure and the secure authentication procedure. We refer to our attacks as Bluetooth Impersonation AttackS (BIAS).Our attacks are standard compliant, and are therefore effective against any standard compliant Bluetooth device regardless the Bluetooth version, the security mode (e.g., Secure Connections), the device manufacturer, and the implementation details. 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.

Since its introduction in 2010, Bluetooth Low Energy (LE) has seen an abrupt adoption by top companies in the world. From smartphones, PCs, tablets, smartwatches to fitness bands; Bluetooth Low Energy is being implemented more and more on technological devices. Even though the Bluetooth Special Interest Group includes and strongly recommends implementations for security features in their standards for Bluetooth LE devices, recent studies show that many Bluetooth devices do not follow the recommendations. Even worse consumers are rarely informed about what security features are implemented by the products they use. The ultimate goal in this study is to provide a mechanism for users to inform them of the security features implemented in a Bluetooth LE connection that they have initiated. To this end, we developed an app for Android phones that extracts the security features of a Bluetooth LE connection using the btsnoop log stored on the phone. We have verified the correctness of our app using the Frontline BPA Low Energy Analyzer.