iPhone developer chpwn first noticed the firmware update and posted a link to it on Twitter. "AppleTV2,1_4.1_8M89_Restore.ipsw," a 242 MB download, is available from Apple's download site.
The iPhone Dev-Team subsequently announced that it had already successfully used SHAtter, an in-development iOS 4.1 exploit, to jailbreak the new Apple TV firmware, Maggadget reports .
"Even though the new AppleTV isnt yet in peoples homes, the firmware is available on Apples normal public distribution servers and SHAtter has been used to decrypt its keys," wrote the iPhone Dev Team on their blog.
Apple began shipping the set-top box on Monday, in time for a September delivery date as promised.
Rumors leading up to the Apple TV's Sept. 1 announcement had suggested that a drastically redesigned Apple TV would run iOS and have access to the App Store. However, when the $99 streaming Apple TV was first revealed, it was unclear whether the device was running iOS.
References to a mysterious iProd device in the USB configuration list for iOS turned out to be for the Apple TV, suggesting that the device would use a modified version of iOS.
Although the new Apple TV isn't setup to run third party apps, a special Apple TV App Store may still be in the works. On Sept. 1, Apple CEO Steve Jobs told Bloomberg BusinessWeek that "when the time is right, Apple could open an App Store for the TV that could do for television sets what all those apps have done for the iPhone."