Netatmo is the latest vendor to be exposed as having weak security to protect user information. The Internet of things (IoT) vendor has several products, including a set of Internet-enabled weather monitoring devices that connect via a user’s WiFi network to communicate with the cloud.
The problem is that the Netatmo was storing user WiFi network passwords, then transmitting them in the clear, without any encryption, as part of a data debug dump. The debug information was sent to the Netatmo cloud service, which enables users to track and monitor weather remotely.
Netatmo devices are widely deployed across the U.S., and the company has an online map that shows where devices are located. The purpose of the map is to help users see weather all around the country. Netatmo data can also be uploaded to the Weather Underground crowdsourced weather platform.
Security researcher Johannes Ullrich of the Internet Storm Center (ISC), itself an organization tasked with reporting on the “weather” conditions of the Internet, was the first person to publicly discover and report the WiFi credential flaw.
Netatmo publicly tweeted on Feb. 13 that it has corrected the flaw and thanked Ullrich for his report.
The issue of dumping a WiFi password in the clear is nontrivial and could have had profound consequences. Potentially anyone in range of a Netatmo device could have sniffed the network traffic and pulled out the unencrypted WiFi password to gain access to a user’s network. Going a step further, given that the data was sent unencrypted, there might well have been a risk about how data is stored on the cloud back end at Netatmo as well.
What’s most interesting about the Netatmo situation though is how Ullrich found the flaw, which actually serves to illustrate how users can protect themselves. Ullrich didn’t debug the device or run some kind of penetration testing exercise. Instead, it was the open-source Snort IPS (intrusion prevention system) on Ullrich’s network that protected him from leaking his WiFi password.
“I do have a custom rule in my Snort rule set, alerting me of the passphrase being sent in the clear,” Ullrich wrote.
Going a step further, Ullrich has provided the rule, which I have now implemented on my own network as it’s delightfully simple and effective. Ullrich’s Snort rule for monitoring of WiFi password leakage is:
alert ip any any -> any any ( sid: 1000284; msg: “WPA PSK Passphrase Leak”; content: “[Iamnotgoingtotellyou]”; )
It seems as though at least once a week, I see reports about some news or study on IoT security. The simple truth is that IoT security is no different from any other former of technology security. Basic hygiene and best practices should always be in place, passwords should be protected, and data should be encrypted.
For users, the lesson is simple: Network segmentation and monitoring is critical. In my own use case for all the IoT devices in my environment, they are on separate VLANs that are isolated from my primary network. In that way, if my IoT toaster for example is exploited, an attacker can’t use it as a way to get into my bank information that is on my primary VLAN network segment.
It’s still early days for many IoT devices, and I suspect this Netatmo incident won’t be the last time we hear about a security issue. Continued vigilance from security researchers and users is the only way the problem will ever get better.
Sean Michael Kerner is a senior editor at eWEEK and Follow him on Twitter @TechJournalist.

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