Two researchers found a way to take advantage of weaknesses in the mobile telecommunications system that allows to legally spy on people. The exploit works by figuring out the cell phone number of virtually anyone, then tracking their whereabouts and even listening to their voice mail, as reported by CNET news.
First, a target’s cell phone number is obtained from a public database that links names to numbers for caller ID purposes. This can be done by anybody operating a private branch exchange (PBX) through spoofing the outgoing caller ID and then automating phones calls to him- or herself, thereby triggering the system to perform a name lookup.
Generating a phone database of the whole US this way would only take a couple of weeks according to Nick DePetrillo, one of the researchers. His fellow researcher Don Bailey points out that this is not illegal nor is it a breach of terms of service.
Once the number has been identified, it is then matched with a geographic location using the Home Location Register (HLR) of the SS7 (Signal System) public switched network which logs the whereabouts of numbers so networks can hand calls off to one another.
This allows for tracking of cell phone users along their routes.
To make matters worse, some providers, such as T-Mobile, are also vulnerable to voice mail spoofing and as a result effectively let perpetrators listen to the victims’ messages.
In addition this enables someone to map a social web of people, their cellular numbers, the content and context of their voice mail and also relationships to others.
Given that this affects not just individual users but also corporations and government agency that have been assigned large blocks of numbers, it might be time to review your security policies to assess and mitigate the impact this might have on you and/or your business.
For assistance in reviewing your security policies as well as assessing and/or mitigating your risk profile, contact us today.
