Apple unsigns iOS 14.2, 14.2.1, and 12.4.9, thwarting downgrades

After officially launching iOS 14.3 to the public last month with new features and improvements, Apple has closed the signing window for iOS & iPadOS 14.2 & 14.2.1, a move that prevents affected iPhone and iPad owners from restoring their handset’s firmware version to anything but the current iOS & iPadOS 14.3 release.

In addition to iOS & iPadOS 14.2 & 14.2.1, the company has officially started unsigning iOS 12.4.9, which prevents older handsets that are incapable of being upgraded to iOS or iPadOS 13 from downgrading from the newer iOS 12.5 release.

Apple first began with unsigning the aforementioned firmware versions a small subset of older handsets earlier this evening. Later on, Apple continued the process for all over handsets.

Anyone who owns an iPhone or iPad should find that this was a predictable move on the Cupertino-based company’s behalf, as Apple regularly stops signing older versions of iOS & iPadOS about a week after a new release becomes available to the public.

Although it’s not generally that common for a user to want to downgrade their installed version of iOS or iPadOS, there are two primary reasons why someone might want to: 1) to make their handset jailbreakable by restoring down to a vulnerable firmware; or 2) to resolve potential bugs that may arise from installing a newly released and poorly tested firmware version.

Before anyone jumps to Apple’s rescue to claim that the latter simply doesn’t happen, one would only need to observe what happened when Apple released iOS & iPadOS 13.2 last year, as the update changed something with application backgrounding that resulted in substantially more aggressive memory management. In other words, the operating system was prematurely force-quitting backgrounded apps without the user’s consent.

While some certainly do downgrade their firmware to fix bugs like the one mentioned above, the obviously more common reason to downgrade your handset’s firmware is to make your handset more vulnerable to the exploits used by modern jailbreak tools. Apple regularly patches software exploits with each new software update, so downgrading to an older version of iOS or iPadOS can increase your odds of jailbreak eligibility (assuming the version you’re restoring to isn’t already jailbreakable).

Since no software-based public jailbreak currently exists for iOS & iPadOS 14.2 or 14.2.1, this news doesn’t really impact the jailbreak community all that much. Only the checkra1n jailbreak was capable of pwning iOS & iPadOS 14.2 & 14.2.1, and it uses a hardware-based exploit that can’t be patched by Apple with any software update.

Apple has a lot to gain from blocking firmware downgrades, and while a lot of it has to do with ensuring that users are taking advantage of all the latest features, bug and stability fixes, and security improvements, the flip side to the story is that Apple gets to corral its users into using the latest firmware available for its platforms, which unequivocally means that the company gets to gloat about new firmware adoption at each Keynote presentation it puts together. But we digress…

Anyone curious about what version of iOS or iPadOS is being signed for their device can use the handy online utility. There, you can select your device type and view the versions of iOS that are and aren’t being signed, in addition to download firmware files directly.

Are you upset that iOS & iPadOS 14.2, 14.2.1, and 12.4.9 are no longer being signed? Share your thoughts in the comments section below.