Attackers can the location of mobile phones find out the number several times to call. It could be burglars, for example, can check whether the phone user is at home, warn researchers.
The attack requires that a phone on a gsm network: it does not work on 3g or 4g. In addition, should the equipment in the vicinity of the person from whom the location outdated, say the researchers from the University of Minnesota in their study, which Ars Technica message.
The technique works by the person from whom the location obsolete and must be, repeatedly calling, and within five seconds of hanging up. In that time looking for the network where the phone is data that the researchers read – but the phone does not ring. Therefore, someone can’t figure out that his location is looked up.
The attack works through leaks in the gsm protocol and requires a laptop, a featurephone with custom firmware and a fixed line to make calls. That setup should be located in the vicinity of the one that is being followed, because the attack works via a LAC, Local Area Code. LACs are the areas in which providers in their networks division.
The practical value of the attack is limited, because it is so laborious. A major limitation is also that it doesn’t work as a phone on the 3g network it: many phones are now by default connected via 3g.