In new research published Tuesday and shared with TechCrunch, Dardaman and Wheeler found three security flaws which, when chained together, could be abused to open a front door with a smart lock.
Smart home technology has come under increasing scrutiny in the past year. Although convenient to some, security experts have long warned that adding an internet connection to a device increases the attack surface, making the devices less secure than their traditional counterparts. The smart home hubs that control a home’s smart devices, like water meters and even the front door lock, can be abused to allow landlords entry to a tenant’s home whenever they like.
he researchers found they could extract the hub’s private SSH key for “root” — the user account with the highest level of access — from the memory card on the device. Anyone with the private key could access a device without needing a password, said Wheeler.
They later discovered that the private SSH key was hardcoded in every hub sold to customers — putting at risk every home with the same hub installed.
Using that private key, the researchers downloaded a file from the device containing scrambled passwords used to access the hub. They found that the smart hub uses a “pass-the-hash” authentication system, which doesn’t require knowing the user’s plaintext password, only the scrambled version. By taking the scrambled password and passing it to the smart hub, the researchers could trick the device into thinking they were the homeowner.