Security News > 2022 > June > WiFi probing exposes smartphone users to tracking, info leaks
Researchers at the University of Hamburg in Germany have conducted a field experiment capturing hundreds of thousands of passersby's WiFi connection probe requests to determine the type of data transmitted without the device owners realizing it.
WiFi probing is a standard process, part of the bilateral communication required between a smartphone and an access point to establish a connection.
Many stores already use WiFi probing to track their customers' position and movement.
They recorded all broadcasted WiFi connection problems for three hours, capturing a total of 252,242 probe requests, 46.4% in the 2.4GHz spectrum and 53.6% in 5GHz. In just three hours, the researchers had 58,489 SSIDs from random passersby, which, in many cases, contained numeric strings with 16 or more digits that were likely "Initial passwords" of popular German home routers from FritzBox or Telekom.
Some of these sensitive strings were broadcasted tens, hundreds, and in some cases, even thousands of times during the three hours of recording through repeated bursts of probing.
Finally, users can completely silence probe requests, which can be done via advanced network settings.