Computers connected to networks are constantly threatened by attackers who seek to exploit vulnerabilities wherever they can find them. This risk is particularly high for machines connected to the Internet, but any network connection can be susceptible to attacks. As highlighted by security researcher and consultant [Rick Osgood], even computers connected to nothing more than a radio can be vulnerable to attacks if they’re using certain digital modes of communication.
The vulnerability that [Rick] found involves exploiting a flaw in a piece of software called WinAPRS. APRS is a method commonly used in the amateur radio community for sending data over radio, and WinAPRS allows for this functionality on a PC. He specifically sought out this program for vulnerabilities since it is closed-source and hasn’t been updated since 2013. After some analysis, he found a memory bug which was used to manipulate the Extended Instruction Pointer (EIP) register which stores the memory address of the next instruction to be executed by the CPU. This essentially allows for arbitrary code execution on a remote machine via radio.
The exploit was found while using Windows XP because it lacks some of the more modern memory protection features of modern operating systems, but the exploit does still work with Windows 10, just not as reliably and with a bit of extra effort required. It’s a good reminder to use open-source software when possible so issues like these can get resolved, and to regularly install security updates when possible. If you’re looking to delve into the world of APRS in more modern times, take a look at this project which adds APRS to budget transceivers. Just make sure you get your license first.