Security researchers have discovered a major security flaw that allows hackers to listen to private phone calls and read text messages even if cellular networks use the latest and most advanced encryption available.
The critical flaw is in the telecommunications network known as Signal System 7, which is used by many mobile carriers around the world, including AT&T and Verizon, and provides the path for calls, text messages and other services between devices. The vulnerability was discovered by German researchers, who will present their findings at a hacker conference in Hamburg later this month.
SS7, or Signaling System Number 7, is a series of protocols used by most telecommunications carriers around the world to communicate with each other when routing calls, SMS, and data. It allows mobile phone companies to collect location information from cell phone masts and share it with someone else. For example, a mobile carrier in the United States will find its customer, regardless of whether he or she is traveling to any other country.
According to security researchers, the outdated infrastructure of SS7 makes it very easy for hackers to break it, as it is loaded with serious vulnerabilitiesthat can lead to a breach of privacy from the billions of mobile phones in circulation around the world.
So far, the extent of the problem and the damage that the hackers may have done is not known, but it is believed that the hackerscan track or redirect users' calls to themselves or anywhere in the world, before forwarding to the normal recipient, and listen to the calls.
No matter how strong or advanced encryption mobile carriers use, for example, AT&T and Verizon use 3G and 4G networks for calls and text messages sent by users on the same network, but using SS7 is insecure for sending data across networks.
