Firecore has released an updated version of Seas0nPass (for Mac) that includes an untethered jailbreak for the AppleTV 4.1.1 (iOS 4.2.1) software. All credit for the untethered jailbreak process goes to the Chronic Dev Team.
Seas0nPass for Windows is also being finalized with the untether and will be available soon. The latest Beta3 version of aTV Flash (black) is compatible with Seas0nPass, GreenPois0n and Pwnage Tool jailbreaks.
Note: If you’ve already jailbroken with GreenPois0n (RC 6.1) you do not need to re-jailbreak – both Seas0nPass and GreenPois0n contain the same jailbreak components.