Hams Unlock the Flexradio Maestro Control Panel, Add Support for Running Arbitrary Software
Exploiting the ability to load Notepad then Explorer, radio amateur Kristoffer Hille and colleagues have significantly improved the Maestro.
Norwegian radio ham Kristoffer Hille has published details of a back door in the Flexradio Maestro radio control panel — allowing custom applications to be executed on the underlying Windows operating system.
"One of the quirks we have run into more often is that the Maestro won’t allow you to connect to networks where you authenticate through usernames and passwords," Hille writes of the Akademisk Radioklubb's experience with the tool, which is an add-on to the Flexradio 6500 designed to allow for use without a controlling computer. "We found that other people also had the same experience and that Flex Radio provided no solution for the use case.
"This left us a bit baffled, especially since we found no reason for this not to be a feature. While experimenting with getting this to work, we discovered a backdoor that gave us access to the file system from within the Maestro software. This, in addition to a bit of exploration within the operating system, made the file system and the device itself fully accessible from a desktop computer within a couple of hours."
That backdoor unlocks the Windows operating system on which the control panel runs, not only allowing for a browser to authenticate the device on otherwise-unsupported Wi-Fi networks but the installation and execution of any custom software — such as the Windows-only SmartSDR computer assisted transceiver tool. " Because the Maestro-application already supports sharing radio data with a desktop computer using the SmartSDR-software," Hille explains, "running both applications on the same device works well."
Initially, Hille did not document the precise nature of the back-door vulnerability in the control panel — but in an update to his original post has revealed exactly how other owners of the Maestro can unlock their own units. "We would like to clarify that this is not exactly a major modification of the device," Hille notes, "but it opens up for people to create scripts and software for the device to enable other functionality. Since the device has a Bluetooth-adapter, using a Bluetooth enabled headset could be possible and enable a even more wire-free radio experience. Regardless, we hope that this backdoor comes in handy for others, and that we can see more projects involving the Maestro."
Hille's documentation on unlocking the Maestro, which relies upon being able to load the Notepad utility from the Flexradio login prompt then using that to load Windows Explorer, can be found on the Akademisk Radioklubb website.