Apple Stops Signing iOS 15.4 Following iOS 15.4.1 Release, Downgrading No Longer Possible

Following the March 31 release of iOS 15.4.1, Apple has stopped signing iOS 15.4, the previously available version of iOS that came out earlier in March. As iOS 15.4 is no longer being signed, it is not possible to downgrade to that version of iOS once you've installed iOS 15.4.1.

iOS 15
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date, so it is not unusual that iOS 15.4 is no longer being signed.

iOS 15.4 was a major update featuring support for unlocking an iPhone while wearing a mask, new emoji characters, Universal Control on the iPad, and tons more.

iOS 15.4.1 added a fix for a battery drain issue on the ‌iPhone‌, but more importantly, it addressed AppleAVD issue that could allow an application to execute arbitrary code with kernel privileges. Apple said this exploit may have been actively exploited, so it is a good idea to update to iOS 15.4.1 if you have not done so already.

Apple has also stopped signing tvOS 15.4 and HomePod 15.4 software.

Related Forum: iOS 15

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Top Rated Comments

Danfango Avatar
29 months ago

Endless updates...more bugs...RedHat LinMac 2000
How dare they inconvenience the user by fixing stuff, protecting the user and improving the product that the user is complaining about!
Score: 8 Votes (Like | Disagree)
vanylapep Avatar
29 months ago
It's a trap.

Once you update your phone to 15.4.1, Xcode 13.2.1 won't allow you to deploy to your phone because it only supports 15.4.0. So you update to Xcode 13.3 but your macOS won't allow it because you're on macOS 11.3 but Xcode 13.3 requires macOS 12.0. So you gota buy a new Macbook.
Score: 7 Votes (Like | Disagree)
Mr. Dee Avatar
29 months ago
I finally upgraded to iOS 15.4.1 from iOS 14.8.1 on my iPhone X and 2017 iPad Pro 12.9. I couldn’t stand the nagging at work anymore. The iPhone X feels like a new phone with the upgrade and I do feel the speed difference. On the iPad there isn’t really not much that feels new but its there. The only other iOS device I have not updated because it failed a couple times is my iPhone 6s.

I took that as a warning sign and leave it be. The watchOS 8.5.1 update failed a couple times, but I just put my S3 next to my X before going to bed and updated the next morning.

So, things are going well otherwise. See you back here next year with iOS 16.
Score: 2 Votes (Like | Disagree)
_Spinn_ Avatar
29 months ago
I'm glad Apple does what it can to stop OS fragmentation.
Score: 2 Votes (Like | Disagree)
winxmac Avatar
29 months ago

I finally upgraded to iOS 15.4.1 from iOS 14.8.1 on my iPhone X and 2017 iPad Pro 12.9. I couldn’t stand the nagging at work anymore. The iPhone X feels like a new phone with the upgrade and I do feel the speed difference. On the iPad there isn’t really not much that feels new but its there. The only other iOS device I have not updated because it failed a couple times is my iPhone 6s.

I took that as a warning sign and leave it be. The watchOS 8.5.1 update failed a couple times, but I just put my S3 next to my X before going to bed and updated the next morning.

So, things are going well otherwise. See you back here next year with iOS 16.
I was on iOS 14.8 then upgraded to iOS 15.4 then I saw that iOS 15.3 RC was still signed at that time so I downgraded to it and still on it at the moment... Upgraded and downgraded using IPSW through iTunes...

In the company I work at, I also receive email notification about needing to go to the latest version otherwise access to company resource will not work... I don't have a work-provided phone and I just decided to upgrade...

Also, note to Apple, re-sign the last update of previous versions so if someone cannot afford to buy a newer model, the device they currently have will still be at least useable although with limited app support...
Score: 2 Votes (Like | Disagree)
leicaman Avatar
29 months ago
When the version that they stop signing has two zero day flaws, there's an inescapable reason to stop letting people downgrade to it.
Score: 2 Votes (Like | Disagree)