Another day, another Internet of Things security problem. This time Belkin, a company that’s been called out before for vulnerable home automation kit, has issued a firmware update that will prevent old school attacks on its WeMo kit that could have let malicious hackers haunt not just customers’ homes, but their Android smartphones too.
The update landed as Invincea Lab researchers Scott Tenaglia and Joe Tanen prepared to talk about the hacks at the Black Hat Europe conference taking place in London this week.
And whilst Belkin’s update addresses the issues, the hackers told it was possible to completely kill the update process on already-compromised devices, preventing any fix from ever being delivered. The first vulnerability uncovered by Tenaglia and Tanen was classed as a SQL injection bug, where they found they could inject data into databases used by WeMo devices. Those databases are used in WeMo systems to remember rules – such as when a light or an oven should automatically turn on. Tenaglia and Tanen found they could insert malicious code into the database that would create a new SQLite file in the WeMo device’s web server root directory.
With some tweaks, that could then create a shell on the device – a shell effectively allowing root (read ‘almost total’) control over the device. As long as a hacker was sitting on the same network as a user, they could carry out the same attack, though the exploit requires the attacker to restart the network connection on the device.
Getting root would actually provide the attacker with more control over the device than the user, the researchers noted. They could play with the rules set out by the user; imagine turning the oven on full blast or switching on the TV in the middle of the night. It’s more likely, the researchers said, that evil hackers would add the devices to a botnet, like Mirai, which was used in massive attacks in late October, causing widespread web outages across Twitter, Amazon Web Services, Netflix and numerous other internet giants. The only way to relinquish that control would be via a firmware update, which Belkin has now provided. Prior to the update, “if you were to unplug it and press the factory reset button and put it back in, that doesn’t remove what we’ve done,” said Tanen.
And, said Tenaglia, it’s easy for hackers to kill the firmware update process and prevent any such clean up. “It’s very simple to break the firmware update procedure so you can actually never update the firmware,” he told me, confirming later in email: “If a device is currently compromised, then attacker could break the update process and prevent this update from taking place.”
The researchers will also be showing how, prior to an August update from Belkin, they could force a Belkin device to infect an Android phone via the WeMo application. When the app tries to connect to a Belkin machine, it beacons out looking for a “friendly” name. The Invincea team found it was possible for hackers on the same network to change that friendly name to an unfriendly one containing malicious code – in this case some rogue javascript. The app would accept the code and execute it. As long as the app was running (or in the background) the code could be used to track the location of the Belkin customer and siphon off all their photos, returning the data to a remote server belonging to the hacker.
Tenaglia thinks such threats – where people’s mobile data is endangered, not just their domestic privacy – should encourage greater vigilance in the IoT community. “It’s a new nuance for IoT security — no one has done anything like this before.”
Belkin fixes
Belkin spokesperson Leah Polk pointed to a previous statement from Belkin, in which it confirmed the Android app issue was fixed in August. The firmware update for the SQL injection vulnerability went live yesterday, she added. “Users will see a firmware update notification when they open their app.” “We have not investigated whether or not we can get around the fix, so all I can say is that our unfriendly name in its current form will not execute,” Tenaglia confirmed.
Whilst Belkin has acted, vast numbers of other IoT machines are being actively compromised. The now-infamous Mirai botnet was made up of vulnerable cameras and DVRs. They contained more easily-exploitable vulnerabilities than the Belkin systems: default usernames and passwords that were widely known.
