Discovering IoT Physical Channel Vulnerabilities
Discovering IoT Physical Channel Vulnerabilities
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DOI：
10.1145/3548606.3560644
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发表时间：
2021-02
期刊：
影响因子：
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通讯作者：
Muslum Ozgur Ozmen;Xuansong Li;A. Chu;Z. Berkay Celik;Bardh Hoxha;X. Zhang
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文献类型：
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作者：
Muslum Ozgur Ozmen;Xuansong Li;A. Chu;Z. Berkay Celik;Bardh Hoxha;X. Zhang
智能家居包含各种传感器和执行器，由提供定制自动化的物联网应用程序控制。以往的研究表明，攻击者可以利用应用程序之间的物理交互漏洞，将用户和环境置于风险之中，例如，如果闯入一所房子，对手打开加热器触发应用程序，当温度超过阈值时，该应用程序会打开窗户。目前，物理交互的安全行为依赖于应用程序代码分析或开发人员手动派生策略的设备状态动态分析。然而，现有的工作无法实现足够的广度和保真度来将APP代码转换为他们的物理行为，或者提供不完整的安全策略，导致准确性差和错误警报。在本文中，我们介绍了一种新的方法，IoTSeer，它将APP代码分析和动态分析与新的安全策略有效地结合在一起，以发现物理交互漏洞。IoTSeer的工作原理是，首先将每个应用程序的传感器事件和执行器命令转换为物理执行模型(PEM)，并统一PEM以表示应用程序的复合物理执行(CPeM)。CPeM允许我们通过定义IoTSeer的执行参数和最少的数据收集来在不同的智能家居中部署IoTSeer。IoTSeer支持带有有意/无意物理通道标签的新安全策略。然后，它通过伪造在CPeM上高效地检查它们，这解决了由于物联网设备的连续和离散行为而导致的验证的不可判断性。我们在一个有14个执行器、6个传感器和39个应用程序的实际住宅中对IoTSeer进行了评估。IoTSeer发现了16个唯一的策略违规行为，而以前的工作只识别了16个中的2个，其中有18个被错误标记的违规行为。IoTSeer只需要为每个执行器收集30分钟的数据来设置CPeM参数，并且适用于新添加、移除和重新定位的设备。
Smart homes contain diverse sensors and actuators controlled by IoT apps that provide custom automation. Prior works showed that an adversary could exploit physical interaction vulnerabilities among apps and put the users and environment at risk, e.g., to break into a house, an adversary turns on the heater to trigger an app that opens windows when the temperature exceeds a threshold. Currently, the safe behavior of physical interactions relies on either app code analysis or dynamic analysis of device states with manually derived policies by developers. However, existing works fail to achieve sufficient breadth and fidelity to translate the app code into their physical behavior or provide incomplete security policies, causing poor accuracy and false alarms. In this paper, we introduce a new approach, IoTSeer, which efficiently combines app code analysis and dynamic analysis with new security policies to discover physical interaction vulnerabilities. IoTSeer works by first translating sensor events and actuator commands of each app into a physical execution model (PeM) and unifying PeMs to express composite physical execution of apps (CPeM). CPeM allows us to deploy IoTSeer in different smart homes by defining its execution parameters with minimal data collection. IoTSeer supports new security policies with intended/unintended physical channel labels. It then efficiently checks them on the CPeM via falsification, which addresses the undecidability of verification due to the continuous and discrete behavior of IoT devices. We evaluate IoTSeer in an actual house with 14 actuators, six sensors, and 39 apps. IoTSeer discovers 16 unique policy violations, whereas prior works identify only 2 out of 16 with 18 falsely flagged violations. IoTSeer only requires 30 mins of data collection for each actuator to set the CPeM parameters and is adaptive to newly added, removed, and relocated devices.