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Hey FCC, when you're not busy screwing our privacy, how about those SS7 cell network security flaws, huh?

No one else seems to care, sniff politicians

US Democrats have written to America's communications watchdog the FCC complaining the mobile industry needs a kick up the backside to fix serious flaws in its networks.

Last week the FCC's Communications Security, Reliability and Interoperability Council (CSRIC) published its final report [PDF] into the Signaling System 7 protocol, which (among many things) allows cellular networks to talk to one another. It concluded that the FCC needs to act to fix SS7's long-standing security shortcomings.

The protocol, designed in the 1980s, is fundamentally insecure, and can allow an attacker or rogue insider with access to a telco's backend to track the location of any mobile phone user, read their messages, and listen in on calls. Security weaknesses in SS7 were exploited in 2014, but so far there has been little effort to replace SS7 with something more secure.

"It is clear that industry self-regulation isn't working when it comes to telecommunications cybersecurity," wrote Senator Ron Wyden (D-OR) and Representative Ted Lieu (D-CA) in an open letter [PDF] to the FCC on Tuesday.

"The continued existence of these vulnerabilities – and the industry's lax approach to cybersecurity – does not just impact the liberty of Americans, it also poses a serious threat to our national and economic security. As such, the FCC must take swift action to address fundamental security threats to our mobile phones, which are no less dangerous than those cybersecurity threats that receive far more attention from other government agencies."

The letter urges the FCC to take action against network operators that refuse to tackle the issue. It warns the American public that they may be at risk, and says the FCC should set up programs to encourage people to use end-to-end encryption – which is one of the CSRIC's key recommendations.

The council's report noted that the SS7 problem isn't just an issue for mobile users, but for wired services as well. SS7 is vital for correctly routing 911 emergency service calls in the US, as well as free 800 numbers.

Thankfully, the report found, if there are bad peeps exploiting SS7 then it's relatively easy to spot with the right network monitoring equipment. The problem is that very few telcos bother to perform such checks.

Some have said that shifting to 5G networks will fix the problem by replacing SS7 with the Diameter protocol. But the CSRIC report concludes that there are also serious security issues with Diameter and researchers have shown it's similarly vulnerable to attack as SS7.

This isn't the first time Wyden and Lieu have raised this problem. Earlier this month the duo wrote to Homeland Security Secretary John Kelly asking about the SS7 issue, although that got no response. Given that the FCC is busy breaking down privacy protections, the Congressfolk should expect the same lack of action as Homeland Security. ®

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