DUMLRacer Root and rollback exploit and remove 905

This document describes how to use DUMLRacer to remove the restrictions introduced by DJI to prevent owners from downgrading from Mavic FW 1.04.0100. DUMLRacer also allows you to enable adb as the root user.

You can run DUMLRacer manually (see the readme in git) or you can use it in DUMLDore 2.11 or higher for point-and-click usage. However, Dumldore does not leave permanent root like DumlRacer.


Get the latest JAR file from Github and put it somewhere on your computer.


DUMLRacer is a commandline Java program. You first need to open a shell window

  • MAC: Open terminal - and cd to the directory where you downloaded DUMLRacer
  • Windows: Open a command prompt, and cd to the directory where you downloaded DUMLRacer
java -jar DUMLRacer.jar <mode>

Modes are AC, RC or GL

  • AC - aircraft
  • RC - remote
  • GL - Goggles

After it is done, it enables root and downgrades. Jezzab has implemented this exploit into DUMLdore. If DUMLdore does what you want, then use it. NOTE however, DUMLDore does NOT apply the root part of the JCase/DUMLRacer exploit

Both races need to be won, you can check with “adb shell”.

The root is most reliable on the 01.04.0100, less so on others. It may take a few minutes to start as well after reboot.

Root access is permanent. It can be removed by doing:

adb shell

and then…

mount -o remount,rw /vendor
rm /vendor/bin/*

Want to remove that pesky 905 NFZ?

from ADB Shell

mount -o remount,rw /amt
cd amt
rm -r nfz

Also check the data/upgrade/backup dir and delete the 905 backup module

Say THANK YOU to jcase: Any donations in excess of the drone cost, will go to Special Olympics!

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