Android_Emuroot is a Python script that allows granting root privileges on the fly to shells running on Android virtual machines that use google-provided emulator images called Google API Playstore, to help reverse engineers to go deeper into their investigations.
Android_Emuroot requires the Google API Playstore emulator to be launched with the qemu gdb stub option enabled, and uses it to alter process metadata stored in memory in kernel task structures. The main idea is to start from a shell with the lowest privileges, then to find its associated credential structure in kernel memory to replace it by another structure having the highest privileges.
Implementing this memory modification on a Google API Playstore emulator presents the following two advantages:
- to work with an environment very similar to a physical device (with production build number, etc.) and with all Google Play and Google services packages already installed. This is often required by the targeted applications
- to have a very easily modifiable memory since a GDB debugger can be attached to the device to fully control the kernel memory
Android_Emuroot requires to already have a working Android SDK. Installing the command-line tools is recommended (downloadable via the Android Studio GUI: Tools > Android > SDK manager > SDK Tools).
Android_Emuroot is a Python script that uses the ADB facilities as well as the GDB facilities from the two following Python's modules:
- pygdbmi (Parse GDB machine interface output with Python)
- pure-python-adb (Pure Python implementation of the ADB client)
Be sure you have these modules or install them via pip: pip3 install -r requirements.txt.
N.B.: Android_Emuroot supports Python 2 and Python 3.
Depending on the hardware architecture and the kernel version of the emulator, the memory layout of the related qemu image varies. Thereby the location of the memory patches implemented by Android_Emuroot varies as well.
For now, Android_Emuroot supports the following versions of emulators:
| Android version | API | Architecture | Kernel | Build |
|---|---|---|---|---|
| Android 7.0 | 24 | x86 | 3.10 | google-api-playstore |
| Android 7.1.1 | 25 | x86 | 3.10 | google-api-playstore |
| Android 8.0 | 26 | x86 | 3.18 | google-api-playstore |
| Android 8.1 | 27 | x86 | 3.18 | google-api-playstore |
Be sure the AVD you want to root is based on one emulator of this list.
N.B.: the emulators can be downloaded via
sdkmanager, a
tool from the Android Studio toolchain, with the GUI or in command line, for
example like this: sdkmanager --install "system-images;android-27;google_apis_playstore;x86".
Then, create an Android Virtual Device (AVD) accordingly, via the AVD manager GUI or
with
avdmanager
like this: avdmanager create avd -n my_avd_name -k "system-images;android-27;google_apis_playstore;x86".
Android_Emuroot needs to interact with both:
- the ADB server of to get information from the emulated device and spawn shells inside
- the GDB server of QEMU to get information about the memory layout of the emulated device and patch values in memory
The scheme below shows the interactions between all the elements:
The Android Debug Bridge
(ADB) is a
command line tool of the Android Studio toolchain that lets communicate with
an Android device. The ADB server is the component that manages communication
between Android_Emuroot and the ADB daemon launched on the device. By default,
ADB servers listen on 127.0.0.1 port 5037. adb start-server lets you
ensure that there is a server running.
Be sure your ADB server is running.
The other requirement to use Android_Emuroot is to attach a GDB server to your
AVD when launching it.
emulator,
another command line tool of the Android Studio toolchain, allows to launch
AVDs with a lot of options. Among them: -qemu -s (shorthang for -qemu -gdb tcp::1234)
which opens a GDB server on TCP port 1234.
Use this option to get a GDB server available.
Here is an simple example of emulator's usage:
emulator -avd my_avd_name [options] -qemu -s
This way, a GDB server will be attached to the AVD my_avd_name and
Android_Emuroot will be able to spawn its GDB client and perform the memory
patches.
Once both ADB server and GDB server are operational, you are ready to use Android_Emuroot.
Android_Emuroot has 3 modes:
single --magic-name NAME: to give root privileges to only 1 shell given in parameteradbd [--stealth]: to give root privileges to the entireadbdserver; each new shell will be spawned as rootsetuid --path NAME: to install a setuid root binary on the file system
More details on the usage and the tool internals: Detailed Usage
Android_Emuroot has been written by Mouad Abouhali and Anaïs Gantet from airbus-seclab.
Android_Emuroot is released under GPLv2.