On Mitel 6869i 4.5.0.41 devices, the Manual Firmware Update (upgrade.html) page does not perform sanitization on the username and path para…

On Mitel 6869i 4.5.0.41 devices, the Manual Firmware Update (upgrade.html) page does not perform sanitization on the username and path parameters (sent by an authenticated user) before appending flags to the busybox ftpget command. This leads to $() command execution.