This version patches a certificate chain validation issue in the handling of X.509 certificates. The vulnerability allows an attacker to capture or modify data in sessions protected by SSL/TLS (and possibly other attacks involving X.509 certificate validation). HT4824 has more info. http://issl.recurity.com/ is a test page that will show if your iDevice is vulnerable.
As there’s no untethered jailbreak for 4.3.4+ yet, users wishing to remain jailbroken can install isslfix in Cydia (from BigBoss) to patch this vulnerability without having to upgrade. 4.3.3 + jailbreakme.com + PDF Patcher 2 + isslfix will give you the jailbroken equivalent of 4.3.5.
I once again noticed that the firmware for the Apple TV is a slightly newer version. It’s still listed as 4.3 (as it was when I posted with the 4.3.1 release, but it’s now labeled as “8F455” instead of “8F202”. It may have changed before this (I manually look through Apple’s XML for these new versions), but this is the first I noticed it.
Apple TV 2G – AppleTV2,1_4.3_8F455_Restore.ipsw