Apple Accidentally Unpatches Vulnerability, Leading to New iOS 12.4 Jailbreak

Apple in iOS 12.4 mistakenly unpatched a vulnerability that was fixed in the iOS 12.3 update, leading to a new jailbreak available for iOS 12.4 devices, reports Motherboard.

Hackers discovered the vulnerability over the weekend and Pwn20wnd created a publicly available, free jailbreak that works on devices running the latest version of iOS or any version of iOS below iOS 12.3.

unc0ver jailbreak 12 4
Most jailbreak code is kept private to keep Apple from patching it, so this is the first time that a public jailbreak has been available in a while. It was apparently discovered when a user tested an older jailbreak on iOS 12.4 and found the patch had been reverted.

Security researcher Jonathan Levin told Motherboard that the accidental vulnerability also once again makes iPhone users vulnerable to a "100+ day exploit," referring to how long the bug has been around.

Ned Williamson from Google Project Zero said that the bug could be exploited to install spyware on a target ‌iPhone‌.

The researcher told Motherboard that "somebody could make a perfect spyware" taking advantage of Apple's mistake. For example, he said, a malicious app could include an exploit for this bug that allows it to escape the usual iOS sandbox--a mechanism that prevents apps from reaching data of other apps or the system--and steal user data.

Another scenario is a hacker including the exploit in a malicious webpage, and pairing it with a browser exploit, according to the researcher.

A third security researcher, Stefan Esser said that people should be careful what apps they download from the App Store right now. "Any such app could have a copy of the jailbreak in it," he wrote on Twitter.

Multiple users have confirmed that the jailbreak works and that their devices have been jailbroken using the new software. Apple has not commented on how or why the vulnerability was unpatched, but the company will likely have a fix available soon.

Popular Stories

iOS 26

15 New Things Your iPhone Can Do in iOS 26.2

Friday December 5, 2025 9:40 am PST by
Apple is about to release iOS 26.2, the second major point update for iPhones since iOS 26 was rolled out in September, and there are at least 15 notable changes and improvements worth checking out. We've rounded them up below. Apple is expected to roll out iOS 26.2 to compatible devices sometime between December 8 and December 16. When the update drops, you can check Apple's servers for the ...
ios 18 to ios 26 upgrade

Apple Pushes iPhone Users Still on iOS 18 to Upgrade to iOS 26

Tuesday December 2, 2025 11:09 am PST by
Apple is encouraging iPhone users who are still running iOS 18 to upgrade to iOS 26 by making the iOS 26 software upgrade option more prominent. Since iOS 26 launched in September, it has been displayed as an optional upgrade at the bottom of the Software Update interface in the Settings app. iOS 18 has been the default operating system option, and users running iOS 18 have seen iOS 18...
iOS 26

Apple Seeds iOS 26.2 and iPadOS 26.2 Release Candidates to Developers and Public Beta Testers

Wednesday December 3, 2025 10:33 am PST by
Apple today seeded the release candidate versions of upcoming iOS 26.2 and iPadOS 26.2 updates to developers and public beta testers, with the software coming two weeks after Apple seeded the third betas. The release candidates represent the final versions of iOS 26.2 and iPadOS 26.2 that will be provided to the public if no further bugs are found during this final week of testing....
Photos App Icon Liquid Glass

John Gruber Shares Scathing Commentary About Apple's Departing Software Design Chief

Thursday December 4, 2025 9:30 am PST by
In a statement shared with Bloomberg on Wednesday, Apple confirmed that its software design chief Alan Dye will be leaving. Apple said Dye will be succeeded by Stephen Lemay, who has been a software designer at the company since 1999. Meta CEO Mark Zuckerberg announced that Dye will lead a new creative studio within the company's AR/VR division Reality Labs. On his blog Daring Fireball,...
iOS 26

When Will Apple Release iOS 26.2?

Monday December 1, 2025 4:37 pm PST by
We're getting closer to the launch of the final major iOS update of the year, with Apple set to release iOS 26.2 in December. We've had three betas so far and are expecting a fourth beta or a release candidate this week, so a launch could follow as soon as next week. Past Launch Dates Apple's past iOS x.2 updates from the last few years have all happened right around the middle of the...
maxresdefault

iPhone Fold: Launch, Pricing, and What to Expect From Apple's Foldable

Monday December 1, 2025 3:00 am PST by
Apple is expected to launch a new foldable iPhone next year, based on multiple rumors and credible sources. The long-awaited device has been rumored for years now, but signs increasingly suggest that 2026 could indeed be the year that Apple releases its first foldable device. Subscribe to the MacRumors YouTube channel for more videos. Below, we've collated an updated set of key details that ...
Intel Inside iPhone Feature

Apple's Return to Intel Rumored to Extend to iPhone

Friday December 5, 2025 10:08 am PST by
Intel is expected to begin supplying some Mac and iPad chips in a few years, and the latest rumor claims the partnership might extend to the iPhone. In a research note with investment firm GF Securities this week, obtained by MacRumors, analyst Jeff Pu said he and his colleagues "now expect" Intel to reach a supply deal with Apple for at least some non-pro iPhone chips starting in 2028....
ive and altman

Jony Ive's OpenAI Device Barred From Using 'io' Name

Friday December 5, 2025 6:22 am PST by
A U.S. appeals court has upheld a temporary restraining order that prevents OpenAI and Jony Ive's new hardware venture from using the name "io" for products similar to those planned by AI audio startup iyO, Bloomberg Law reports. iyO sued OpenAI earlier this year after the latter announced its partnership with Ive's new firm, arguing that OpenAI's planned "io" branding was too close to its...
iphone air camera

iPhone Air's Resale Value Has Dropped Dramatically, Data Shows

Thursday December 4, 2025 5:27 am PST by
The iPhone Air has recorded the steepest early resale value drop of any iPhone model in years, with new data showing that several configurations have lost almost 50% of their value within ten weeks of launch. According to a ten-week analysis published by SellCell, Apple's latest lineup is showing a pronounced split in resale performance between the iPhone 17 models and the iPhone Air....
iPhone 17 Pro Cosmic Orange

iPhone 17 Pro Lost a Camera Feature Pro Models Have Had Since 2020

Thursday December 4, 2025 5:18 am PST by
iPhone 17 Pro models, it turns out, can't take photos in Night mode when Portrait mode is selected in the Camera app – a capability that's been available on Apple's Pro devices since the iPhone 12 Pro in 2020. If you're an iPhone 17 Pro or iPhone 17 Pro Max owner, try it for yourself: Open the Camera app with Photo selected in the carousel, then cover the rear lenses with your hand to...

Top Rated Comments

Wiencon Avatar
82 months ago
Honest question... do people still really jailbreak like that? Like, how big is the jailbreak community now?
I love questions like that. Yeah, the community is quite big, the jailbreak subreddit has over 300k subscribers and after last couple of releases it seems to be gathering some popularity.

Stock iOS 12 is great, but jailbreaking it is a no-brainer for me, especially when we can jailbreak the newest and signed version (which is a very rare opportunity)
I can tell you why I jailbreak all my iOS devices (SE and two X's)

- You can get real split screen multitasking with the https://www.idownloadblog.com/2019/04/23/pullover-pro/

- You can have ANY app on the CarPlay screen with https://www.redmondpie.com/carbridge-for-ios-12-jailbreak-released-lets-you-use-any-app-with-carplay/

- You can get all iPhone X gestures on older devices without any lags, bugs, with the https://www.idownloadblog.com/2019/03/18/neptune-for-iphone/

- You can have customizable Answering machine, record messages to the device and even set different greetings for different callers with https://www.idownloadblog.com/2018/08/23/answeringmachine-x/

- You can get rid of the full screen calling screen which users have been asking for ages with https://www.idownloadblog.com/2019/03/06/callbar-xs-brings-everyones-favorite-phone-call-centric-jailbreak-tweak-to-ios-12/

- You can stack icons together instead of using folders which looks extremely cool with https://www.idownloadblog.com/2018/12/03/zenith/

- You can get amazing gestures in app switcher screen with https://www.idownloadblog.com/2019/05/04/gesto/

- You can get the grid switcher from iPad in your iPhone with https://www.idownloadblog.com/2019/03/11/newgridswitcher/

- You can have custom shortcuts on lockscreen with the https://www.idownloadblog.com/2018/04/20/jumper/

- You can write notes on your lockscreen with the https://www.idownloadblog.com/2018/08/30/notepad/

- And hundreds of small things

Jailbreaking is not only about some themes, you can really get the 100% from your iPhones instead of the 60% or less that Apple gives you.
My jailbroken SE can do more than stock XS (without any performance issues) and that is not an exaggeration

I think that now is an amazing opportunity to try jailbreaking, you have nothing to lose. If anything happens (which is extremely unlikely because jailbreaks now aren't permanent/untethered) you can easily restore your device to the newest stock iOS version with iTunes and forget about everything
Score: 30 Votes (Like | Disagree)
Unity451 Avatar
82 months ago
I really wish that I had the surplus of time that hackers always seem to have.
Score: 20 Votes (Like | Disagree)
jsmith189 Avatar
82 months ago
Honest question... do people still really jailbreak like that? Like, how big is the jailbreak community now?
Score: 16 Votes (Like | Disagree)
AppleFan91 Avatar
82 months ago
I wish Apple was on its game, but alas, no. It's a company spread too thin, governed by greedy hand-wringers.
Yes yes, and Apple is doomed and Steve is rolling in his grave like a gas station hotdog
Score: 13 Votes (Like | Disagree)
mannyvel Avatar
82 months ago
I'm surprised this regression happened. This points to a breakdown in product management discipline, which in general is a bad sign.
Score: 12 Votes (Like | Disagree)
BarredOwl Avatar
82 months ago
I wish Apple was on its game, but alas, no. It's a company spread too thin, governed by greedy hand-wringers.
Score: 11 Votes (Like | Disagree)