Back when the Chromecast first came out, users were able to get root access to the device to give it some extra function, but Google quickly fixed that and since then, root hasn’t been achievable. However now a few hardware hackers have found a new vulnerability in the latest Chromecast update that can be exploited to give Chromecast owners root access.
The method is called “HubCap” and works on both brand new and already running Chromecasts. Using root access, you can modify the dongle to suit your needs. Unfortunately this method does require you to use a USB development board called Teensy. You can see the full demo of this method in action below and check out the XDA forum for full instructions.
Via: Chrome Story