We just saw a recent post here on SpiderLabs Anterior about one of mostly used functionalities used on mobile devices and it's applications and how this could be exploited by malware apps and real criminals. Unfortunately, this is not the only piece of information mobile devices are mostly sharing with the humanity.
Last week I presented at the BayThreat conference some concerns about a possible combination of facts that shows the mobile ecosystem today:
- The ease of configuration/ usability
- the behavior of some technologies implemented on these devices
- how some combinations of those could affect the privacy of the users.
So, what does this all mean?
Any electronic device capable of using the internet (phone, media player, computer, tablet, laptop computer) has a name associated to it. When one first starts any of these devices, there is a configuration phase/ wizard when the users name these devices. Most of these wizard programs ask the user for the user's name, and not the name the user wants to give to the device. The result of this is that many devices out there are named something like FirstName-LastName-TypeOfDevice. Is this a problem? Not necessarily, let's put that aside for a second.
Once a device joins a local network (home, work, hotspot), there are several ways to "get to the internet", and all of these ways try to be the more transparent as possible for the user. Obviously, in a corporate network, some security controls should be in place and the user might have to go through some additional steps to get to the network. At home, the user might simply have a passphrase for the WiFi network, at a hotspot a web-portal login and so on.
In the background, several things happen and our usual network protocols are out there. Part of the usability experience, devices have to be discovered or in a very transparent way to the user, find other devices on the network.
Some of the protocols used are very application specific, like controlling your media player using your tablet. Other protocols are out there for the device to discover and be discovered. In one of these protocols, what do we see?
I am sure at this point you understand the implications of this in a public hotspot for example. But other similar protocols will give out information from corporate networks, like company names, domain names that might reveal regional offices names/ locations, etc.
There are other "discover-like" multicast based protocols, in either ipv4 or ipv6 that attention could be spent on.
But the device has to be connected to a network in order for any protocols to communicate, correct? Yes.
What happens when a device has its WiFi interface on but doesn't connect to anything? It repeatedly cycles through the list of known networks.
Known networks are, at least a very good amount of the ESSIDs a device has been connected to. And that is simply how WiFi works, although one should be able to delete WiFi profiles from a device. Could this be a privacy problem?
It will always depend on the context.
Let's analyze the made-up list below assuming it is the list of ESSIDs a mobile device not connected to any network will be looking for to connect:
Coffee Shop
McCarran WiFi
Airline VIP Lounge
DENTISTSCON2011
MEGAHUGEVEGASHOTEL
Miami Airport WiFi
SALON VIP AEROLINEA
AEROPUERTO INTERNACIONAL
UNIVERSIDAD FEDERAL
Hospital General
Putting a little thought on it and use of foreign language skills, we can safely assume this person is in the dentistry field, went to Las Vegas for a conference, had a connection in Miami, probably flies a lot since it has access to airlines lounges, lives in a Spanish speaking country and probably also teaches at an University on top of working at a hospital.
The example above seems to be a little bit overkill, but it is not. The ESSIDs at most of the public places have really obvious names; sometimes companies also use ESSID names that will give away where the person who owns that device works.
All of the above is mostly food for thought, but if you start putting all of this together, our trusty mobile devices could easily reveal very important information about us.
