Apple’s huge database, which usually records the locations of Wi-Fi base stations to the nearest metre, has apparently been exploited without hindrance: With little effort, attackers are able to create a ‘global snapshot’ of all the location data of the WLANs recorded there. This allows them - over a longer period of time - to track changes in the location of the routers usually belonging to a household or sometimes even of individuals, as two researchers from the University of Maryland have now demonstrated.
The researchers consider it particularly problematic that Apple’s Wi-Fi database can be read out practically unhindered and immediately provides the location data for ‘several hundred’ additional BSSIDs (the physical MAC addresses of the routers) to the requesting client without being asked via an apparently unlimited API. In this respect, Apple’s Wi-Fi database also differs fundamentally from other Wi-Fi databases, such as the one operated by Google.
It seems that Apple may be interested in at least requiring authentication that the query comes from an Apple device (or even an Apple-approved API key), which would go a long way in alleviating the security flaw.
I can see some value in the server returning BSSID location data directly (especially with risk of intermittent or slow data connections), but the combination of all the factors seems sloppy.
It could even be privacy preserving with the right implementation. With a bunch of device locations nearby you’re not hitting the server constantly and leaving a trail… but I think Apple just had limiting API hits and maybe computing.