The new Amazon Fire HD 8 tablet, released only a few months ago, has been rooted, as spotted by Liliputing. Better yet, the rooting method was achieved by unlocking the bootloader through a chip exploit that the creator of the rooting method claims can only be patched by changing the hardware of the tablet.
A detailed guide for this new rooting method has been posted on XDA Forums. Achieving root is done strictly through software, but the method does involve opening the case of the Fire HD 8 tablet because you must temporarily short/connect two points of the device’s circuit board to put the bootrom into download mode in order for the device to accept the modified software. There’s a possibility that the method will be refined in the future to not require opening up the tablet, but it seems to be relatively easy to do as-is and requires no soldering.
Another requirement of the current rooting procedure is a Linux PC, but this too may be improved soon to include Windows PCs and Macs. In short, the rooting procedure requires prying open the back of the tablet to locate the “CLK” test point on the circuit board, connecting the “CLK” test point to ground with a wire or paper clip, running the provided script on a Linux PC which will wait for the tablet to be connected, and then connecting the tablet to the Linux PC with a micro USB cable while the “CLK” test point is grounded. From there, the provided scripts take care of the rest.
The result is a Fire HD 8 tablet that is rooted with an unlocked bootloader and TRWP custom recovery installed. Having the bootloader unlocked in addition to being rooted, versus just being rooted, means that the tablet will be much easier to recover if you make a mistake, since an unlocked bootloader means you can flash custom boot and system images. This rooting method goes so deep that it can also be used to recover a bricked tablet that was previously ruined through a botched firmware downgrade.
Right now, this rooting method is only available for the latest 2018 version of the Fire HD 8 tablet, but the creator says that “the vulnerability is present on every MediaTek [CPU] device,” so this is very likely just the start for this rooting method. There are already people working on adapting this rooting method to older Fire HD 8 models, as well as the current Fire HD 10 tablet. While the vulnerability is the same across all of these devices, the scripts must be adapted for each device due to different memory addresses and offsets.
The Fire TV 2, Fire TV Stick 2, and Fire TV Stick 4K all use MediaTek CPUs that are likely vulnerable to this same exploit. If the bootrom of those device’s can be put into download mode and someone adapts the rooting method to the Fire TV’s specific hardware addresses, then we might see new Fire TV rooting methods in the near future. I’ll, of course, be keeping a very close eye on how this all unfolds.