SS7 Vulnerability - Be careful about what you say on your Cell Phone,

From the Article

The German researchers found two distinct ways to eavesdrop on calls using SS7 technology. 

• In the first, commands sent over SS7 could be used to hijack a cell phone’s “forwarding” function -- a service offered by many carriers. Hackers would redirect calls to themselves, for listening or recording, and then onward to the intended recipient of a call. Once that system was in place, the hackers could eavesdrop on all incoming and outgoing calls indefinitely, from anywhere in the world.
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• The second technique requires physical proximity but could be deployed on a much wider scale. Hackers would use radio antennas to collect all the calls and texts passing through the airwaves in an area. For calls or texts transmitted using strong encryption, such as is commonly used for advanced 3G connections, hackers could request through SS7 that each caller’s carrier release a temporary encryption key to unlock the communication after it has been recorded.

Follow this link for additional details:

http://www.washingtonpost.com/blogs/the-switch/wp/2014/12/18/german-researchers-discover-a-flaw-that-could-let-anyone-listen-to-your-cell-calls-and-read-your-texts/