Following the release of iOS 6.1.3 for the range of iDevices, Apple has also released a firmware version 5.2.1 to second and third generation Apple TV users, and with it has patched the Evasi0n Untethered Jailbreak.
Just like in iOS 6.1.3, Apple has closed all three security holes used by the Evad3r team for the Untethered Jailbreak in firmware release 5.2.1, as stated in the Apple bug tracker:
Available for: Apple TV 2nd generation and later
Impact: A local user may be able to execute unsigned code
Description: A state management issue existed in the handling of Mach-O executable files with overlapping segments. This issue was addressed by refusing to load an executable with overlapping segments.
CVE-2013-0977 : evad3rs
However, in addition to the security patches, various bugs are fixed and under-the-hood enhancements were introduced with the release, but the big feature is the new redesigned Hulu Plus app.
Right away, you’ll notice we’ve added content categories across the top navigation bar to make it easy to for you to jump to your chosen section – whether it is TV, Kids, Latino, Search, or something else. Inside each category, you’ll discover what’s new in our content library so it’s easy to discover new shows and keep up with the shows you already love. You can also jump into your favorite shows right away with the “Shows You Watch” tray. We built this to make sure you never miss a new episode or lose your place in a series.
Of course, Apple TV users have the option of upgrading to the new 5.2.1 release, or preserving their old version and the Jailbreak, but forfeiting the new Hulu Plus app. If you do upgrade, there is a potential that a tethered Jailbreak may be released in the near future, but as things stand it is recommended you do not upgrade.