Posted: January 3rd, 2013 | Author: cj_000 | Filed under: GTVHacker | Tags: Custom Recovery, Exploit, Generation 2, GTVHacker, Hisense, Recovery, Root, sony, Vizio | Comments Off
A little over 2 years ago a band of miscreants came together from an XDA developers forum post and started working together to get privileged code execution on the Google TV. Little did we know that the challenges would be greater than anyone could imagine.
When the Google TV was released it was easily one of the most locked down Android devices containing a signature enforced bootloader which established a “chain of trust” between it and every component loaded thereafter. The hardened state of the kernel the device came with made things even worse, with the kernel enforcing module signing as well as lacking most of the popular Android vulnerabilities that were plaguing the mobile world. This Android device was truly unlike most others.
So we began work attempting to win an advertised cash bounty for being the first to gain root access on the newly released device. After some work, we posted the first root method for the Logitech Revue, winning a $500 prize. Since then it has been our goal to make Google TV an open platform by unlocking each released device. There were plenty of challenges along the way, in the form of long nights reversing code and many bricked devices. But along with the challenges there have also been many triumphs in the form of releases.
Going over some of our biggest acheivements in the last 2 years:
- Found and released a hardware root method for the Logitech Revue and assisted Dr. Dan Rosenberg in finding a software root exploit.
- Found and released multiple exploits for the Sony NSZ-GT1 and Sony Google TV television line, breaking the established chain of trust.
- Received a secret message from Logitech within the stock recovery on the Logitech Revue.
- Released our own customized and completely open Google TV kernel which utilized a chain of exploits to execute.
- Had the opportunity to present at the 20th annual “DEFCON” security conference in which we we teased a root exploit for the newly released NSZ-GS7 but are still waiting to leverage it until more hardware comes out.
- While working on porting the Boxee OS to the Google TV we found and released 2 exploits which have enabled the Boxee community to install a popular modification package known as Boxee+.
- We released a modification package for the Hisense Pulse which leveraged the intial debug configuration of the device for root, disabled automatic updates, and modified the flash plug-in allowing you to watch Hulu and other previously blocked content providers.
In regards to the future of GTVHacker, over the past month we found and have been developing an exploit which will allow for custom kernels to be run on most of the newest generation of Google TV devices. We’ve also (cj_000 specifically) been busy making a custom recovery specifically designed for the Google TV. You may already know this but, there are a number of differences between the Google TV and other Android devices and these difference make it impossible to simply build a popular AOSP based recovery or kernel image. Due to these differences, we had to make our own recovery from scratch. At the time of writing this it’s still in a beta phase and rather simple. It only allows for installation of an update.zip package from usb. This can be a modified update, a superuser binary and apk or whatever else you wish. We’ve also started adb over ethernet to allow for custom system changes that may require more interaction than a update package.
Below is a quick demo of the custom recovery mentioned above being tested on a Sony NSZ-GS7 Google TV device. We currently don’t have a release date set as we are trying to keep most of the specifics private in order to avoid an update that could patch the exploit before the community gets to utilize it. We just wanted to give the community a sneak peek at what we’ve been working on privately over the last few months. So sit tight, 2013 will be a great year for the Google TV and GTVHacker!
Posted: December 22nd, 2012 | Author: zenofex | Filed under: GTVHacker, Hisense, Root | Tags: google, Hisense, Pulse, Root, TV | 2 Comments »
The day has finally arrived, the Hisense Pulse has launched and is finally in our hands. Upon first look we were impressed with the speed of navigation from within the menus. If you have experience with the previous generation of the Google TV platform then you’ll recognize the Pulse’s UI which seems to be almost identical to that of the Logitech Revue. The form factor of the Pulse is similar in size and shape to that of the already released Vizio Co-Star, and the motherboard layout makes it seem like they used a similar design. One difference between the Co-Star and the Pulse is that the Pulse’s remote is much more intuitive and its use feels more natural. All together it’s exactly what someone would expect for another device in the Google TV family but with one of the cheapest prices in its generation.
Our biggest and most unexpected surprise came within moments of our first examination of the Pulse. Upon receiving any new hardware, partially because of our previous experience with the Revue, we like to start off disassembling the hardware even before powering on a device. After doing so in this particular instance we found that a hardware root-shell is enabled by default through the serial console header on the device’s motherboard. Better yet, the root-shell is available in both recovery and normal boot which allows for tinkering of the device in both modes of operation. While we’ve seen serial consoles left in prior Google TV devices (see: Logitech Revue), we had yet to see a Google TV device that included a shell within both normal and recovery mode, let alone one in the second generation of the Google TV platform. While leaving a hardware shell leaves the box almost completely vulnerable its use still requires some soldering experience. However, after further exploration we noticed a 4 pin header on the Pulse PCB which allowed us to simply plug in a common connector and avoid soldering all together! This adapter is conveniently in a location that can be accessed by either temporarily opening the device and plugging in the adapter, or for more permanent use, by cutting a hole in the side of the case. The ease of access to the pin header as well as the obvious oversight of the serial console was just the beginning of our findings.
After finishing up our quick analysis of the hardware we finally had the opportunity to explore how the device’s software side was configured. We found that even with the hardware root oversight being as unexpected and less secure than any of its counter parts, the software side was worse. After browsing through the system’s init scripts, and checking the props, we noticed that a simple “adb root” to the device would restart adb as root therefore providing us with a root shell via adb.
Why is this device so much less secure than any of the other Google TV devices? Is this an oversight, or did someone at Hisense purposely leave it there to show community support? We hope that someone did this purposely as it would be great if a manufacturer or Google finally embraced the modding community, but it was probably just an oversight.
Knowing this, we thought it would be best to release our findings for the community as soon as possible as it will likely be patched quickly with the next automatic update. However, if you do have a Hisense Pulse and would like to take advantage of root before it’s possibly patched. We have a package that will perform a few community desired modifications such as:
- Install Superuser.apk and su binary to device.
- Patch flash player to allow content to be played from previously blocked websites (Hulu, Fox, CBS, NBC, etc.).
- Disable automatic updates to preserve root (can easily be reversed).
You can find information on our modification package at the GTVHacker Wiki page for the Hisense Pulse
We have more coming soon, check back around the first of the year for a sneak peek at something even more awesome than this!
Looking to purchase a Hisense Pulse and also want to support GTVHacker? [Use this link to purchase at Amazon]