WiFi’s friendliness to other devices can pose a significant threat in the wrong circumstances. Researchers from the University of Waterloo have discovered a vulnerability in the networking standard that allows attackers to track devices through walls. The technique identifies a device’s location within 3.3 feet simply by taking advantage of WiFi devices’ automatic contact responses (even on password-protected networks) and measuring response times. You can identify all of the connected hardware in a room and even track people’s movements if they have a phone or smartwatch.
The scientists tested the exploit by modifying an off-the-shelf drone to create a flying scanning device, the Wi-Peep. The robotic plane sends multiple messages to each device as it flies around to pinpoint the locations of the devices in each room. A thief using the drone could find vulnerable areas in a home or office by checking for the absence of surveillance cameras and other signs that a space is being monitored or occupied. It could also be used to follow a security guard or even help competing hotels spy on each other by measuring the number of rooms in use.
There have been attempts to exploit similar Wi-Fi problems, but the team says these typically require bulky and expensive equipment that would give away attempts. Wi-Peep requires only a small drone and around $15 in equipment, which includes two WiFi modules and a voltage regulator. An intruder could quickly scan a building without revealing his presence.