It always happens. A technology used for spying on people always opens up security vulnerabilities. Sony's "rootkit" DRM had huge security vulnerabilities
that let people do bad things to your computer. And now comes the news that the LANrev system used by the Lower Merion School District to secretly photograph students at home
also just happened to have a big security vulnerability
that, in theory, made it possible for others to spy on children without them knowing it as well:
The LANrev program contains a vulnerability that would allow someone using the same network as one of the students to install malware on the laptop that could remotely control the computer. An intruder would be able to steal data from the computer or control the laptop webcam to snap surreptitious pictures....
The vulnerability in the LANrev system lies in the symmetric-key encryption it uses for authentication between the client and the server, and isn’t related to the optional Theft Track feature. Therefore, even computers that are not using the theft feature are potentially vulnerable.
The authentication key is stored in the client-side and server software and is fairly easy to decipher, says Frank Heidt, president and CEO of Leviathan. It took Leviathan just a few hours to determine that it’s a stanza from a German poem. The key is the same for every computer using LANrev.
The LANrev client software on a computer is configured to contact a server every minute or so to check in and see if the server has any commands for it. Knowing what the key is would let an attacker who has installed a sniffer on the network intercept that ping and masquerade as the server in communication back to the laptop. It requires the attacker to be on the same network as the target machine -- for example, on a wireless network at the school or anywhere else that offers free Wi-Fi the student might use.
To be fair, there's no evidence that anyone used this hack outside of the researchers who have discovered it, but it still raises more questions about the wisdom of using such software, especially on laptops used by kids.