Kim Zetter reports on Wired that a security researcher created a cell phone base station at DefCon in Las Vegas that tricks cell phones into routing their outbound calls through his device, allowing the interception of calls, even encrypted calls, in the clear.
The low-cost, home-brewed device, developed by researcher Chris Paget, tricks phones into disabling encryption and records call details and content before they are routed on their proper way through voice-over-IP. This device mimics more expensive devices already used by intelligence and law enforcement agencies, called IMSI catchers, that can capture phone ID data and content. The devices essentially spoof a legitimate GSM tower and entice cell phones to send them data by emitting a signal that’s stronger than legitimate towers in the area.
Paget’s system costs only about $1,500, as opposed to several hundreds of thousands for professional products. Most of the cost is for the laptop used to operate the system.