Feeds

Hackers crack femtocells to pwn then clone phones

"You should be ditching femtocells altogether"

  • alert
  • submit to reddit

SANS - Survey on application security programs

Black Hat 2013 Security researchers have warned against the industry's use of femtocells after successfully hacking into two popular models of femtocell, allowing them to intercept voice and SMS information from nearby mobile devices.

The exploit was detailed by iSEC Partners at the Black Hat conference in Vegas after being revealed earlier in July, and affects two femtocells used by Verizon and one repackaged Verizon box put out by Sprint which have already been remotely patched.

Femtocells are used to extend the range of broadcast signals in hard to reach places, and work by creating a secure IP-SEC tunnel between themselves and their carriers larger network. If signal is lacking or poor, then phones will automatically hop onto a nearby femtocell.

The researchers believe it is the first time an exploit has been disclosed against femtocells produced by US carriers. The exploit has been verified to work on 2009 SCS-26UC4 and a 2010 SCS-2U01 femtocell from Verizon.

The exploit saw the researchers gain access to the femtocells via interfacing with an HDMI port on the base of the device, then gaining root access to the stripped-down Linux system inside.

Once inside the system, they were able to implement methods for intercepting and decoding both voice and SMS track – data proved too difficult. They also developed a technique for cloning the phone, allowing people to surreptitiously listen in to calls.

Though these vulnerabilities have been subsequently patched, the researchers are not confident in the continuing integrity of the femtocell as an architecture. This is because the hardware can never be totally locked down by the vendor, and so there will always be some kind of exploit, they reckon.

"There are over 30 carriers worldwide who have femtocells," Tom Ritter, a security consultant at iSEC Partners explained. "Clearly there are issues here. You could of course harden the actual device [but] there's nothing you can do on the platform to prevent physical attackers getting in. There are lots of ways to break onto a physical device."

Another route would be to have carriers mandate that femtocell users register expected numbers with the operator in advance, "but we don't think it is enough," they said.

They instead recommend the use of secured VoIP on WiFI, when out of tower range, or the use of secure end-to-end encryption via apps, of which ones made by Whisper Systems and Silent Circle would be examples.

"Really, you should be ditching them altogether. We're just pretty nervous about giving random people like yourselves cellphone towers and [you] breaking into them." ®

High performance access to file storage

More from The Register

next story
Obama allows NSA to exploit 0-days: report
If the spooks say they need it, they get it
Mounties always get their man: Heartbleed 'hacker', 19, CUFFED
Canadian teen accused of raiding tax computers using OpenSSL bug
Samsung Galaxy S5 fingerprint scanner hacked in just 4 DAYS
Sammy's newbie cooked slower than iPhone, also costs more to build
Snowden-inspired crypto-email service Lavaboom launches
German service pays tribute to Lavabit
One year on: diplomatic fail as Chinese APT gangs get back to work
Mandiant says past 12 months shows Beijing won't call off its hackers
Call of Duty 'fragged using OpenSSL's Heartbleed exploit'
So it begins ... or maybe not, says one analyst
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.