SSL Pinning bypass (Android Emulator)

NeeNee
2 min read

Over the weekend, I was taking a look at an application which implemented SSL pinning. Here's the technique I used to bypass pinning and view the raw requests sent to the application server which then helped me to uncover crucial details about the application's functionality.


Prerequisites

  • An android emulator of choice

  • Burpsuite (installed on host machine)

  • Python packages

    • objection

      If you face issues post-installation:

        pip install --upgrade setuptools
      
    • frida

    • frida-tools


Configure Burp Proxy

on host

on emulator


Install Certificate onto emulator

Launch the browser and head to http://burp and download the CA Certificate.

Make sure to rename the cert to <name>.cer via the file manager.

Then head to the certificate settings on the respective emulator and install the newly downloaded certificate.


Frida Server

Releases · frida/frida (github.com)

download the unzip the respective frida-server versions, extract it and move it to the bin location of your emulator. In my case : D:\Program Files\Nox\bin

adb devices

verify that the adb interface is attached to the device.

adb push frida /data/local/tmp

Push the frida binary to the device via ADB.

D:\Program Files\Nox\bin>adb shell

cd /data/local/tmp/
chmod +x frida

Give the binary execute permissions.

./frida &

Run frida server in the background.


Bypass SSL Pinning

There are a ton of scripts developed by the community for frida which you can find here. We'll be making use of the frida-multiple-unpinning script for our use case.

frida --codeshare akabe1/frida-multiple-unpinning -U -f com.twitter.android

We can verify that the X AKA twitter app has opened up and the SSL pinning bypass is in effect.

We can then take a look at burp and ensure that we are able to see the raw requests sent by the X app to its api server.

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All things Information Security!