Amazon has released a new version of firmware OS software update for Kindle reading device, which has the version number of 3.1. The Kindle update version 3.1 features a few enhancements including secondary display of real page numbers that corresponding page numbers on physical books in order to make cross-referencing easier.

The new firmware update 3.1 for Kindle also patches and breaks all existing jailbreak or hack that been done on the Kindle 3.0, by patching an exploit which allows Kindle to be tricked into running a custom jailbreak and payload hack script simply by redirecting a signed script using a syslink. Anyway, a hacker named Yifan Lu has managed to find another exploit or loophole which allows Kindle 3.1 to be jailbreak and owned, by taking advantage on how Amazon updater checks the signature and uses the “cat” command to load the update files, which allows unsigned script with a space in the file name to be run in between without signature check to jailbreak and own the system. This newest version of the jailbreak for Kindle removes the need for the “ENABLE_HACK_UPDATES” file and uses NiLuJe’s method of bind mounting.

Jailbreak a Kindle allows user to perform several actions onto the device, including ability to install custom fonts, custom screensavers, or enable USB networking and tethering. However, by jailbreaking, it also means that the Kindle warranty may be voided.

For the people who wants to jailbreak the Kindle running on firmware version 3.1, download the Yifan’s Kindle Jailbreak 0.4:

To install the jailbreak, just copy the .bin corresponding to your Kindle model onto the root of your Kindle USB drive. Then, go to Settings, press Menu, and choose Update Your Kindle. There is no need to uninstall older version of jailbreak, as the installer will automatically uninstall all previous versions of jailbreak, with the exception of NiLuJe’s jailbreak.

Update Prefix -> Kindle Model

  • k3w -> Kindle 3 WiFi
  • k3gb -> Kindle 3 WiFi + 3G (non-US/Canada model)
  • k3g -> Kindle 3 WiFi + 3G (US/Canada model)
  • dxi -> Kindle DX White (International)
  • dxg -> Kindle DX Graphite
  • dx -> Kindle DX White (US only 3G)
  • k2i -> Kindle 2 (International)
  • k2 -> Kindle 2 (US only 3G)

In addition to Kindle 3.1, the jailbreak should work with every Kindle version from 2.0 to 3.1, and has been tested on Kindle 3 running on firmware version 3.0.3 and 3.1.

The jailbreak will allow you to install custom hack updates along with official Kindle updates from Amazon. However, just make sure that you uninstall all custom updates before you uninstall the jailbreak, as it’s impossible to run custom packages until the Kindle is jailbroken again.