Posts Tagged: Trane ComfortLink

Feb 16

IoT Reality: Smart Devices, Dumb Defaults

Before purchasing an “Internet of things” (IoT) device — a thermostat, camera or appliance made to be remotely accessed and/or controlled over the Internet — consider whether you can realistically care for and feed the security needs of yet another IoT thing. After all, there is a good chance your newly adopted IoT puppy will be:

-chewing holes in your network defenses;
-gnawing open new critical security weaknesses;
-bred by a vendor that seldom and belatedly patches;
-tough to wrangle down and patch

In April 2014, researchers at Cisco alerted HVAC vendor Trane about three separate critical vulnerabilities in their ComfortLink II line of Internet-connected thermostats. These thermostats feature large color LCD screens and a Busybox-based computer that connects directly to your wireless network, allowing the device to display not just the temperature in your home but also personal photo collections, the local weather forecast, and live weather radar maps, among other things.

Trane ComfortLink II thermostat.

Trane ComfortLink II thermostat.

Cisco researchers found that the ComfortLink devices allow attackers to gain remote access and also use these devices as a jumping off point to access the rest of a user’s network. Trane has not yet responded to requests for comment.

One big problem is that the ComfortLink thermostats come with credentials that have hardcoded passwords, Cisco found. By default, the accounts can be used to remotely log in to the system over “SSH,” an encrypted communications tunnel that many users allow through their firewall.

The two other bugs Cisco reported to Trane would allow attackers to install their own malicious software on vulnerable Trane devices, and use those systems to maintain a persistent presence on the victim’s local network.

On January 26, 2016, Trane patched the more serious of the flaws (the hardcoded credentials). According to Cisco, Trane patched the other two bugs part of a standard update released back in May 2015, but apparently without providing customers any indication that the update was critical to their protection efforts.

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