German researchers discover huge security flaw that allows voice calls and text messages to be intercepted

German researchers discover huge security flaw that allows voice calls and text messages to be intercepted
A report out of Sydney on Saturday morning carries some frightening information for those who long for privacy when communicating on their mobile phones. German researchers have discovered a major security flaw on the SS7 network used by the world's mobile carriers to send voice calls, texts and other content across the globe. The report states that this flaw allows hackers to listen in to private calls and intercept text messages even when encryption is employed.

The researchers behind the report plan on going public with it during a hacker conference to be held in Hamburg later this month. The SS7 network was built in the 1980's, well before anyone could have foreseen the amazing growth in cellular communications. The Germans who worked on the study found that there is very little security on the network, which allows hackers to do their thing while calls are being handed off from cell tower to cell tower.

While individual carriers spend a ton of money trying to sure up their networks, the SS7 pipeline still must be used for calls and texts between carriers. The researchers discovered two ways that hackers could listen in on voice calls. One way is to take over the call forwarding function on a mobile phone, and redirect calls to a hacker's phone for real-time eavesdropping or recording. The call would then be sent through to the proper recipient with the hackers listening in or taping the conversation. The second method uses an antenna to catch all calls and texts being sent through the airwaves. These would be recorded by the hackers, who could request a temporary encryption key from the carrier of each caller. The key would be used on the recordings to break the code.

Tests proving the vulnerability of SS7 have been successfully run over 20 global carriers, including T-Mobile in the U.S. T-Mobile responded to this information with a statement that said, "T-Mobile remains vigilant in our work with other mobile operators, vendors and standards bodies to promote measures that can detect and prevent these attacks." Some messaging apps use their own end-to-end enctryption which allows them to workaround the usual text connections. That is why apps like Apple's iMessage and WhatsApp probably would be safe from hackers taking advantage of the SS7 security breakdown.

After word leaked out in the summer of 2013 that the NSA was collecting metadata that could give them a phone's unique serial number, the location and duration of a call, and the time the call was made, mobile phone users started to see a "G-man" around every corner. And while not an event that was specifically related to mobile communications, the recent hacking of Sony Pictures brought the level of paranoia up another notch.

German Senator Thomas Jarzombek, who allowed his mobile phone to be used by the researchers for testing, summed up the feelings of many who desire complete privacy while on the phone. He recently said, "After all the NSA and Snowden things we've heard, I guess nobody believes it's possible to have a truly private conversation on a mobile phone. When I really need a confidential conversation, I use a fixed-line" phone."

source: SydneyMorningHerald via textually.org

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15 Comments

1. Benoit

Posts: 57; Member since: Oct 16, 2014

Internet packets are not routed through this network, so the main reason while Whatsapp and iMessage are not vulnerable (along with the other internet messaging applications such as Hangout, ...) is simply because they dn't rely on that network, not really because they use encryption.

2. Planterz

Posts: 2120; Member since: Apr 30, 2012

So...no more nekkid celeb pics?

5. dimas

Posts: 3235; Member since: Jul 22, 2014

That naked celeb pics was a different issue. iCloud's fault for having weak security system.

3. Alan01

Posts: 561; Member since: Mar 21, 2012

Exactly what we wrote. Alan F.

7. Benoit

Posts: 57; Member since: Oct 16, 2014

" Some messaging apps use their own end-to-end enctryption which allows them to workaround the usual text connections. That is why apps like Apple's iMessage and WhatsApp probably would be safe from hackers taking advantage of the SS7 security breakdown." It's not because they use encryption, it's because SS7 is the signalling network, which is not used when routing packets to the internet. SS7 is mainly used for Voice (no VoIP), SMS and MMS. Thus, all internet-based services do not make use of SS7, which make then de-facto non-vulnerable to this security flaw. Encryption has nothing to do with it. The article is just a bit misleading on that ;)

9. Augustine

Posts: 1043; Member since: Sep 28, 2013

Only voice and SMS. MMS used data to send messages. Carriers often use different solutions to deliver MMS. That's why MMS from one carrier to another may be cumbersome.

10. Benoit

Posts: 57; Member since: Oct 16, 2014

Maybe I'm wrong, but if I remember correctly, to deliver an MMS, a message (similar to an SMS) containing an URI to the actual payload is pushed to the device through the standard signaling system, and the device has to pull the content according to the URI (which is the part that differ from carrier to carrier).

11. Augustine

Posts: 1043; Member since: Sep 28, 2013

You're right. Thanks for the correction.

12. kevin91202

Posts: 640; Member since: Jun 08, 2014

Ummm. No. You wrote the exact opposite. Pay attention.

13. kevin91202

Posts: 640; Member since: Jun 08, 2014

"Exactly what we wrote." -Alan F. Wrote what? Do you even understand what you wrote? PA user Benoit is saying that you are mistaken to think that iMessage and WhatsApp's are not affected by SS7'S vulnerability because of their encryption. As Benoit and others have poingnantly pointed out, it has nothing to do with encryption -- those apps don't use SS7 for messaging. In other words, you are wrong and we are right.

14. Benoit

Posts: 57; Member since: Oct 16, 2014

You should calm down, There is no reason to get upset or anything, it was just a small precision to the article.

15. cheetah2k

Posts: 2140; Member since: Jan 16, 2011

Need VoLTE asap!

4. dimas

Posts: 3235; Member since: Jul 22, 2014

So ss7 is an obsolete technology. How about blackberry and nokia phones? These phones have heavy encrypting systems.

8. Benoit

Posts: 57; Member since: Oct 16, 2014

It does not depend on your phone, it depends on you carrier. If your carrier uses this technology, and your smartphone is compatible with this carrier, then it is vulnerable since the flaw is in the network, not in the phone ;)

6. xondk

Posts: 1904; Member since: Mar 25, 2014

ss7 sounds to have worked quite well, but sounds like it is time for an update.

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