Showing posts with label Bootloader. Show all posts
Showing posts with label Bootloader. Show all posts

26/04/2016

Exploring Qualcomm's Secure Execution Environment

Welcome to a new series of blog posts!

In this series, we'll dive once more into the world of TrustZone, and explore a new chain of vulnerabilities and corresponding exploits which will allow us to elevate privileges from zero permissions to code execution in the TrustZone kernel.

This may sound familiar to those of you who have read the previous series - but let me reassure you; this series will be much more exciting!

First of all, this exploit chain features a privilege escalation which is universal across all Android versions and phones (and which requires zero permissions) and a TrustZone exploit which affects a very wide variety of devices. Secondly, we will dive deep into an as-of-yet unexplored operating system - QSEE - Qualcomm's Secure Execution Environment. Lastly, we'll see some interesting TrustZone payloads, such as directly extracting a real fingerprint from TrustZone's encrypted file-system.

In case you would like to follow along with the symbols and disassembled binaries, I will be using my own Nexus 6 throughout this series, with the following fingerprint:
    google/shamu/shamu:5.1.1/LMY48M/2167285:user/release-keys 

You can find the exact factory image here.

 

10/02/2016

Unlocking the Motorola Bootloader

In this blog post, we'll explore the Motorola bootloader on recent Qualcomm Snapdragon devices. Our goal will be to unlock the bootloader of a Moto X (2nd Gen), by using the TrustZone kernel code execution vulnerability from the previous blog posts. Note that although we will show the complete unlocking process for this specific device, it should be general enough to work at-least for most modern Motorola devices.

Why Motorola?


After reporting the previous TrustZone kernel privilege escalation to Qualcomm, I was gifted a shiny new Moto X. However... There was one little snag - they accidentally sent me a locked device. This was a completely honest mistake, and they did offer many times to unlock the device - but where's the fun in that? So without further ado, let's dive into the Motorola bootloader and see what it takes to unlock it.