DJI AeroScope Mobile signature bypass in firmware update process

Description

Improper verification of cryptographic signature (CWE-347) in the firmware update handler of the management service (uavmonitor_usbv1) of the 1300 communications board in DJI AeroScope Mobile (TP703) firmware 03.00.00.26, with 1300 communications board firmware 02.00.07.12 through 02.00.08.40, allows an unauthenticated attacker on the local network to install modified firmware, which gives persistent code execution as root. The device accepts any image that matches an MD5 checksum supplied in the same request and does not verify a signature. Exploitation requires network access to TCP port 16000 on the board and that the unit is not connected to another controlling host. Reproduced by running the unmodified device binaries in emulation; not tested on a physical device. NOTE: This vulnerability only affects products that are no longer supported by the maintainer. DJI has discontinued AeroScope Mobile and no fixed firmware is available.