Tag Archives: mobile

Verizon Launches Voice Cypher Secure VoIP Mobile App… With A Government Backdoor

Verizon Wireless this week did something that initially seemed quite impressive – they launched “Voice Cypher”, an app available for iOS, Android and Blackberry that promises secure end-to-end encryption. It uses VoIP and is an “over-the-top” (OTT) app that works on any carrier.  If you read the marketing material on their web site, it all sounds great!  Indeed their “Learn More” page has all the right buzzwords and security lingo – and says quite clearly: Voice Cypher provides end-to-end encryption between callers, even if the call crosses over multiple networks.” They include the requisite network diagram that shows how it protects against all threats:

Verizon Wireless Voice Cypher

It turns out there’s just one small little detail … as reported by BloombergBusinessweek, the app comes complete with a backdoor so that Verizon could decrypt the phone calls if requested to do so by law enforcement!

As the Businessweek article states:

Cellcrypt and Verizon both say that law enforcement agencies will be able to access communications that take place over Voice Cypher, so long as they’re able to prove that there’s a legitimate law enforcement reason for doing so.

Unfortunately, in this post-Snowden era I don’t know that many of us put a great amount of trust in our governments to only access communications with a “legitimate law enforcement reason”.  Or perhaps the concern is that what gets classified as “legitimate” can be widely construed to mean almost anything.

The article does point out that Verizon is bound by CALEA to provide lawful intercept  to the phone networks, but points out an interesting caveat that Verizon could have used:

Phone carriers like Verizon are required by U.S. law to build networks that can be wiretapped. But the legislation known as the Communications Assistance for Law Enforcement Act requires phone carriers to decrypt communications for the government only if they have designed their technology to make it possible to do so. If Verizon and Cellcrypt had structured their encryption so that neither company had the information necessary to decrypt the calls, they would not have been breaking the law.

A Verizon Wireless representative indicated that they believe government agencies looking for ways to protect sensitive information may be  customers of this service, as may be corporate customers concerned about leaking private information.

But… as we continue to hear more and more information about the massive amount of pervasive monitoring and surveillance by government agencies from many different governments around the world, you do have to wonder how safe those agencies and companies will feel with a “secure” solution that already comes with a backdoor.  The problem with a known backdoor is that even if you may trust Verizon Wireless to only allow legitimate law enforcement access… how do you know that some attacker may not be able to penetrate that backdoor?   The “secure end-to-end encryption” isn’t entirely secure.

Given that the service has a higher price tag of $45 per month per device, I do wonder how many businesses or agencies will actually embrace the service.

On reading about this Voice Cypher service, it certainly sounds quite interesting.  We need more secure voice solutions out there – and it’s very cool that Verizon Wireless is delivering this as an OTT mobile app that will work across different carriers.

It’s just too bad that it’s not truly “secure end-to-end”.  🙁

P.S. I also recorded an audio commentary on this same topic.

Skype for iOS/iPhone Vulnerable to Cross-Site-Scripting (XSS) Attack

News from the SUPEREVR security blog is that Skype for iOS is vulnerable to a cross-site scripting (XSS) attack that allows an attacker to send someone a message and, for instance, capture that user’s address book from their iPhone.

The author of the article posted a video that demonstrates the attack:

He further states in a tweet that he notified Skype of the vulnerability on August 24th:

In case anyone is wondering, I disclosed the vulnerability to Skype on 8/24. I was told an update would be released early this month.

Skype has issued a statement through their PR firm:

We are working hard to fix this reported issue in our next planned release which we hope to roll out imminently. In the meantime, we always recommend people exercise caution in only accepting friend requests from people they know and practice common sense Internet security as always.

Skype’s mitigation recommendation is a good one as the default privacy setting is typically that you can only receive chat messages from people on your Contact list. Therefore, the attacker would have to be someone who you have authorized and added to your contact list.

Meanwhile, hopefully Skype will be out with their update soon.

P.S. Hat tip to Tom Keating for writing about this exploit as that was where I first learned of it.

New Android Malware/Trojan Records Your Phone Calls

AndroidtrojanNews out of the CA Security Advisor Blog today is that there is a new piece of Android malware that records phone calls that you make on an Android phone. The post author, Dinesh Venkatesan, goes into some detail about what they found – and how they found it – in testing this malware.

While this is not a “VoIP” issue, per se, as the trojan seems to record calls over the “regular” phone connection it is a general communications security issue and something we all have to watch out for. Over on the ReadWriteWeb, Dan Rowinski published a good piece putting this malware in context with other recent Android malware.

The net of both posts is that ultimately you need to be extremely careful about the source of applications you are installing on your Android phone – and what permissions you are granting them.

Meanwhile, I expect that we’ll continue to more creativity coming out of the attacker community..

Image credit: CA Security Advisor Blog

GSM Encryption Cracked – Eavesdropping Now Possible

Last Friday there was news out of the Chaos Computer Club Congress in Berlin that two security researchers, Karsten Nohl and Sylvian Munaut, had successfully cracked the encryption used in the GSM cellular network. While not “VoIP”, per se, this is of interest to any of us working with VoIP as many VoIP clients are now working on “smartphones” running on top of the GSM network (like, oh, the iPhone, among others). Some of the articles on this topic:

The researchers are apparently not releasing their toolkit publicly, but obviously word of their success will encourage others to investigate further.

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