On the process of fixing privacy issues in Wi-Fi enabled devices

Several practical privacy issues have been uncovered in Wi-Fi technologies since 2016. Those issues allow an attacker to defeat address randomization, an anti-tracking mechanism, and thus to track users of wireless devices in the physical world. As recently demonstrated by Martin et. al, OS developers and vendors are deploying fixes, and the number of vulnerable devices is progressively decreasing. After presenting a comprehensive overview of three active attacks, we conduct a number of experiments to assess whether those issues have been fixed. Using a sample of Wi-Fi enabled devices we found that although some issues have been corrected, some devices remain vulnerable and expose their users to tracking. We analyze the implementation of countermeasures in wpa_supplicant, the software component in charge of Wi-Fi features in Linux and Android. We found that, even if countermeasures have been available for several years in wpa_supplicant, they are still not always included or activated in deployed OS. We discuss the reasons behind this lack of protection.