Apple blocks downgrades to jailbreakable firmware by unsigning iOS & iPadOS 13.5

Apple this evening stopped signing iOS & iPadOS 13.5, a move on the Cupertino-based company’s behalf that essentially prevents iPhone and iPad users from installing this particular version of its firmware whether downgrading from a newer version of the mobile operating system or upgrading from an earlier version.

The move comes approximately one week after Apple released iOS & iPadOS 13.5.1 to the general public specifically with the intention of patching the 0-day kernel vulnerability that Pwn20wnd implemented into the unc0ver jailbreak to add support for iOS & iPadOS 13.5, the latest version of Apple’s mobile operating system at the time.

While revoking signage of older versions of iOS and iPadOS is par for the course for Apple, this particular unsigning inflicted a serious burn on the jailbreak community as Pwn20wnd’s new 0-day exploit permitted jailbreak hopefuls to pwn the current version of iPhone and iPad firmware as it was still being signed. This is something that rarely happens anymore, as Apple is quick to patch vulnerabilities before hackers can use them.

Because iOS & iPadOS 13.5 can no longer be easily restored to, users are now effectively prevented from downgrading or upgrading to a jailbreakable version of iOS or iPadOS, which locks these individuals into a mandatory vanilla loop until the next version of iOS can be pwned on all handsets.

It’s worth noting, however, that handsets ranging from the iPhone 5s to the iPhone X can still be jailbroken regardless of firmware version thanks to the checkra1n jailbreak tool, which utilizes a hardware-based bootrom exploit called checkm8 that can’t be patched by Apple in a software update. With that in mind, even the current 13.5.1 release can be jailbroken with checkra1n as long as the user sports a supported handset.

While Apple’s decision to prevent downgrades to iOS & iPadOS 13.5 has implications for the jailbreak community at this time, we should also address the other side – that is, Apple’s responsibility to keep its users secure from potential hacks that may utilize these exploits for malicious purposes.

Without these updates, Apple would unquestionably be burned at the stake by some for allowing its users to be compromised, so there’s definitely a push-pull in terms of opinion depending on which camp you identify with. Still, we think it would be ideal for Apple to give users the choice to install older versions of iOS or iPadOS if they wanted to, obviously accepting responsibility for themselves if choosing to do so.

Apple benefits from this decision in more ways than one, however, as forcing users to upgrade to the latest version of iOS with each restore helps the company gloat at its Keynote events about how good its new firmware adoption is. Sometimes, however, we wonder what those numbers would actually look like if Apple gave users the choice…

As always, you can see which firmware versions are being signed for every one of Apple’s devices with the handy online utility.

Are you sad to see that iOS & iPadOS 13.5 are no longer being signed following an energetic period of excitement for the jailbreak community? Let us know your feelings in the comments section below.