Conference PaperPDF Available

Breaking Fitness Records Without Moving: Reverse Engineering and Spoofing Fitbit

Authors:

Abstract and Figures

Tens of millions of wearable fitness trackers are shipped yearly to consumers who routinely collect information about their exercising patterns. Smartphones push this health-related data to vendors’ cloud platforms, enabling users to analyze summary statistics on-line and adjust their habits. Third-parties including health insurance providers now offer discounts and financial rewards in exchange for such private information and evidence of healthy lifestyles. Given the associated monetary value, the authenticity and correctness of the activity data collected becomes imperative. In this paper, we provide an in-depth security analysis of the operation of fitness trackers commercialized by Fitbit, the wearables market leader. We reveal an intricate security through obscurity approach implemented by the user activity synchronization protocol running on the devices we analyze. Although non-trivial to interpret, we reverse engineer the message semantics, demonstrate how falsified user activity reports can be injected, and argue that based on our discoveries, such attacks can be performed at scale to obtain financial gains. We further document a hardware attack vector that enables circumvention of the end-to-end protocol encryption present in the latest Fitbit firmware, leading to the spoofing of valid encrypted fitness data. Finally, we give guidelines for avoiding similar vulnerabilities in future system designs.
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Message Type Device Type Encrypted Packet?
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... Finally, they recommended approaches for avoiding matching incoming vulnerabilities in system techniques. They made use of several tools in that experiment such as mitmproxy on Linux, Wireshark, STN32 ST-LINK Utility, a digital multimeter, a soldering iron, thin gauge wire and flux, tweezers, a soldering heat gun, the ST-LINK/v2 in a circuit debugger/ programmer, and the STM32 ST-LINK utility [20]. ...
Article
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Purpose: The use of wearable devices to monitor aspects of personal health is increasing. The Fitbit is an example of a popular device used for this purpose. It is unknown whether users’ privacy (i.e. sensitive data collected from wearable devices) would be leaked via unauthorized access. So, this investigation will answer the following questions; are the data transmissions protected against unauthorised access or modification? what data are transmitted between the device and the server? how much data can be collected by unauthorized access? Method: This paper describes an investigation into data access in the Fitbit Blaze and, specifically, whether this is possible without connecting to the Fitbit server. A Man-In-The-Middle (MITM) attack was used in this investigation. Result: In this experiment, the firmware image, transferred when the device connects to the Fitbit server, is first captured and analysed to obtain data. This was done to attempt to identify the encryption method and obtain the unique device MAC address. Secondly, some fitness data, namely, the authentication key, the cryptographic key and the Nonce, were extracted from the Fitbit application. We attempted to connect the Fitbit Blaze device and the Fitbit application directly without connecting via the Fitbit server. We also attempted direct access to the Fitbit Blaze using a charger cable. In addition, Fitbit Java files were extracted from the Fitbit application. Conclusion: Finally, the outcomes of this investigation are compared with investigations into other Fitbit devices in the previous research.
... In some cases, capturing and analyzing the network traffic will help to determine update intervals. [43] The assessor might be able to capture parts of or the complete firmware and source code. ...
Thesis
Internet-of-things (IoT) devices can improve the efficiency and availability of medical examinations by great lengths. Although IoT healthcare devices often store or process sensitive information or perform operations that could seriously harm a patient if tampered with, the security, safety and privacy in medical devices often lags behind the modern state-of-the-art. While the results of security breaches can be financially devastating or harmful to health, these issues are weighed against the positive effects the usage of medical devices bring forth. To contribute to the development of secure and safe medical devices, this thesis provides an overview of technical background information of medical devices. This thesis will introduce a novel methodology for the assessment of security, safety and privacy in IoT healthcare devices by describing crucial steps in the assessment of IoT devices as can be found in existing approaches for security testing and by an adaption to the characteristics of medical devices. To evaluate our methodology we conducted a study with five seasoned security testers. The study showed that the methodology provides a stable framework for security assessments of IoT healthcare devices and that is able to successfully guide testers in their practical work. The study revealed that methodologies polarize security testers and that the participants did not know any methodology with outstanding usability. The participants expressed their wish to be better-informed when testing products of the critical infrastructure, while stating that the proposed methodology contained unnecessary details. To handle the discrepancy between the vast amount of information a security tester needs and his wish for information being presented in small chunks, security researchers need to find a way to provide centralized and authoritative information and should consider developing dynamic strategies to address the dynamic problem of securing devices in times of ever faster technological progress and changing regulations.
... Numerous nodes are vulnerable to this kind of attack due to the security flaws and weak authentication mechanisms. For instance, the lack of encryption of some devices enables attackers to seamlessly hijack communications and capture private data such as session identifiers, passwords and health data [291,293,303,305,313,[336][337][338]. Of further concern, studies HAVE also discovered MitM-enabling vulnerabilities in protocols integrated in implantable medical devices [339,340]. ...
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Court sets legal precedent with evidence from Fitbit health tracker
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AV TEST Analysis of Fitbit Vulnerabilities
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Wearable tech market to be worth $34 billion by 2020
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Forbes. Wearable tech market to be worth $34 billion by 2020.
Husband learns wife is pregnant from her Fitbit data
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Mashable. Husband learns wife is pregnant from her Fitbit data. http://mashable. com/2016/02/10/tbit-pregnant/, Feb. 2016.
Security Analysis of Wearable Fitness Devices (Fitbit)
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Britt Cyr, Webb Horn, Daniela Miao, and Michael Specter. Security Analysis of Wearable Fitness Devices (Fitbit). https://courses.csail.mit.edu/6.857/2014/les/ 17-cyrbritt-webbhorn-specter-dmiao-hacking-tbit.pdf, 2014.