Globalstar satellite transmissions used for tracking truck fleets and wilderness hikers can be hacked to alter messages being sent with possibly dire consequences for pilots, shipping lines, war correspondents and businesses that use the system to keep an eye on their remote assets.
The technique, described at Black Hat 2015, can't affect control of the Globalstar satellites themselves, just the messages they relay, but that could mean altering the apparent location of assets the system tracks. So a cargo container with a satellite location device in it could be made to seemingly disappear, or an airplane could be made to seem to veer off course, according to a briefing by Colby Moore, a security staffer at Synack.
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He even spun out a scenario where an armored truck might be hijacked, but the hijackers could send signals that indicated it was still following its assigned route while the robbers made their getaway.
The flaw that he exploited has to do with the data protocol itself, it's unlikely that it can be patched, he says, given the inaccessibility of the satellites and the limitations of the transmitting devices themselves that are issued to customers.
The transmitters know where they are via geolocation and transmit that data over the company's array of satellites and down to ground stations. From there messages are relayed via terrestrial means to the customer that is tracking the plane or truck or person carrying the transmitter.
Using information he gleaned from Federal Communications Commission about the system as well as from product specifications from companies that make component parts for the transmitters, Moore reverse-engineered the protocols they use. Then he injected extra data into the stream being sent to the satellite.
His hack is more of a proof of concept and it revealed that the date sent over the network isn't encrypted and is hackable using off-the-shelf components that cost less than $1,000. He says he's going to post the details of how he did it on GitHub in a day or two.
Part of his work included cloning a transmitter so it could send messages that seemed to come from a legitimate device.
The hack would need to be refined in order to be put into practice, Moore says. He only injected data in the upstream traffic, not the downstream traffic, for example, and he wasn't able to process in realtime the information being sent. To do that he would need sophisticated computing equipment like that found in ground stations. So a practical exploitation of the system would require considerable resources.
He says it's not surprising that the protocol isn't encrypted since it was likely created in the 1990s when encryption key distribution was difficult.
Moore says he told Globalstar about his discovery about six months ago and received this response: "Like all companies and industries in the 21st century ... Globalstart monitors the technical landscape and its systems to protect our customers. Our engineers would know quickly if any person or entity was hacking our system in a material way, and this type of situation has never been an issue to date. We are in the business of saving lives daily and will continue to optimize our offerings for security concerns and immediately address any illegal actions taken against our company."
Moore says he is a Globalstar customer who uses its service while he's backpacking in the wilderness so he can be found if something goes wrong.