Hackers have proven just how urgently a gaping flaw in the global telecoms network, affecting what's known as Signalling System No. 7 (SS7), needs to be fixed. In a video demonstration, shown to Forbes ahead of publication today, benevolent hackers from Positive Technologies were able to take control of a Coinbase bitcoin wallet and start pilfering funds via the SS7 flaws.
SS7 weaknesses, despite fixes being available for years, remain open. They allow anyone with access to that part of the telecoms backbone to send and receive messages to and from cellphones, with various attacks allowing silent interception of SMS texts, calls and location data. (Typically, the SS7 network is used by telecoms companies to talk with one another, normally for shifting customers between operators when roaming).
In their attack, the Positive researchers first went to Gmail, using Google's service to find an email account with just a phone number. Once the email account was identified, the hackers initiated a password reset process, asking one-time authorization codes to be sent to the victim's phone. By exploiting SS7 weaknesses they were able to intercept text messages containing those codes, allowing them to choose a new password and take control of the Gmail account. They could then simply head to the Coinbase website and do another password reset using the email they'd compromised.
Scary SS7 attacks
This isn't just a threat that affects bitcoin, of course. It affects anything linked within the Gmail account, not to mention the complete loss of all those emails and the entire Google account. "This hack would work for any resource - real currency or virtual currency - that uses SMS for password recovery," said Positiv...