Apple has released the Apple TV 5.2.1 software update. Hulu users will notice that the Hulu interface has been completely redesigned, including category enhancements and other UI tweaks.
The update also addresses a number of security issues on the Apple TV, including one in which a local user may be able to execute unsigned code. In a security document, Apple describes the issue: "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."
Other security fixes include changes to the kernel, including the ability for a local user to determine the address of structure in the kernel: "An information disclosure issue existed in the ARM prefetch abort handler. This issue was addressed by panicking if the prefetch abort handler is not being called from an abort context."
A third issue that allowed a user to execute arbitrary code in the kernel was also fixed: "The IOUSBDeviceFamily driver used pipe object pointers that came from userspace. This issue was addressed by performing additional validation of pipe object pointers."
Users can manually check for software updates on their Apple TV by selecting "Settings -> General -> Update Software".