Seas0nPass is a new jailbreak tool designed by FireCore specifically and exclusively for the AppleTV 2 (no other iOS devices support). This magic piece of software allows you to jailbreak your atv2 with the latest 4.1.1 (iOS 4.2.1) software by creating custom AppleTV IPSW files and restoring them in iTunes (similar to the existing Pwnage Tool app). It also includes a simple ‘tethered boot’ option which aids in using newer AppleTV firmwares when an ‘un-tethered’ jailbreak is not yet available.
Seas0nPass is available for free, and is open source (the source code is available on Github). It’s Mac only (OSX 10.6 or later) for now but the Windows version should be released soon.
Here are the instructions on how to use Seas0nPass to jailbreak the Apple TV 2: