  The concept of Internet of Things (IoT) has become more popular in the modern
era of technology than ever before. From small household devices to large
industrial machines, the vision of IoT has made it possible to connect the
devices with the physical world around them. This increasing popularity has
also made the IoT devices and applications in the center of attention among
attackers. Already, several types of malicious activities exist that attempt to
compromise the security and privacy of the IoT devices. One interesting
emerging threat vector is the attacks that abuse the use of sensors on IoT
devices. IoT devices are vulnerable to sensor-based threats due to the lack of
proper security measurements available to control use of sensors by apps. By
exploiting the sensors (e.g., accelerometer, gyroscope, microphone, light
sensor, etc.) on an IoT device, attackers can extract information from the
device, transfer malware to a device, or trigger a malicious activity to
compromise the device. In this survey, we explore various threats targeting IoT
devices and discuss how their sensors can be abused for malicious purposes.
Specifically, we present a detailed survey about existing sensor-based threats
to IoT devices and countermeasures that are developed specifically to secure
the sensors of IoT devices. Furthermore, we discuss security and privacy issues
of IoT devices in the context of sensor-based threats and conclude with future
research directions.
