By embedding HTML and JS calls into an MP3, Yifan Lu was able to hook into undocumented debug functions in order to execute code at root level. Not only did Amazon leave a function that allowed any process to be spawned as root, they also didn’t bother to sanitize inputs when reading the ID3 tag for display. With root access, a simple SSH package was created and pushed, providing unfettered access to the device.
Yifan Fu is encouraging other developers to start writing plugins for the device. Open formats such as ePub or Mobi can be supported as well. While apps and games are a possibility, the e-ink display will really limit the possibilities due to the slower refresh rate, lack of color as well as lack of multitouch.
It’s very possible that the Kindle Fire isn’t the only device that Amazon is selling at a loss, with attempts to make up revenues by users purchasing content. Amazon should be concerned as it may open the door for users to permanently store content past the expiration date.