A USB-based vulnerability that allows for the brute forcing of a passcode on an iOS device has been discovered by security researcher Matthew Hickey, reports ZDNet.

The method, which bypasses the 10-entry attempt that erases an iOS device when the setting is enabled, allows a hacker to plug an iPhone or iPad into a computer and send all passcodes, from 0000 to 9999, all at once, triggering an input routine that takes priority over anything else on the device. Hickey demos the hack in the video below.

"Instead of sending passcodes one at a time and waiting, send them all in one go," he said.

"If you send your brute-force attack in one long string of inputs, it'll process all of them, and bypass the erase data feature," he explained.

All that's required to use this brute force password cracking method is an iPhone or iPad that's turned on and locked and a Lightning cable, according to Hickey. It works on iOS devices up to iOS 11.3.

Hickey's iPhone cracking method takes between three and five seconds for each four-digit passcode, which means it's slow and not as advanced as other passcode cracking methods employed by companies like Grayshift, which makes the GrayKey box. For this method to guess a six-digit passcode, Hickey says it would take weeks.

Apple in iOS 12 is introducing a new USB Restricted Mode that may put a stop to the vulnerability that Hickey has discovered, as well as vulnerabilities exploited by tools like the GrayKey Box.

ios12usbaccessoriessetting
With USB Restricted Mode, enabled by default on iOS devices running iOS 12, USB access to an iPhone or iPad is cut off if it's been more than an hour since the device was last unlocked.

That means computers and other accessories can't be used to access a locked iPhone if it's been locked for over an hour, disabling access via a USB to Lightning cable.

Update: In a statement obtained by iMore, Apple says "the recent report about a passcode bypass on iPhone was in error, and a result of incorrect testing."

Top Rated Comments

B4U Avatar
91 months ago
Up to iOS 11.3...
Opens settings > general > about > version
Sees 11.4, close settings and move on with life.
Score: 23 Votes (Like | Disagree)
asdavis10 Avatar
91 months ago
Interesting bug.

Maybe instead of just coming up with ideas, Apple needs to have a team who’s job is to try to break or break into every Apple device. They should be full time employed with their sole mission being to find and exploit every possible weakness.
Somehow you seem to think that an almost trillion dollar company doesn't do this. Fact of the matter is that everything has a vulnerability. It's just a matter of how practical the exploit actually is for it to be useful.
Score: 13 Votes (Like | Disagree)
jonblatho Avatar
91 months ago
Testing and engineering design seem to have taken a backseat to thinness recently.
Great, this tired point again.

Apple has different employees who do different things. What you’re suggesting here is like asking a school custodian to take over a classroom from a teacher.
[doublepost=1529717755][/doublepost]
Up to iOS 11.3...
Opens settings > general > about > version
Sees 11.4, close settings and move on with life.
The iOS 11.4 security content notes ('https://support.apple.com/en-us/HT208848') don’t specify anything seemingly related to this bug.
Score: 9 Votes (Like | Disagree)
flyinmac Avatar
91 months ago
Interesting bug.

Maybe instead of just coming up with ideas, Apple needs to have a team who’s job is to try to break or break into every Apple device. They should be full time employed with their sole mission being to find and exploit every possible weakness.
Score: 7 Votes (Like | Disagree)
centauratlas Avatar
91 months ago
Testing and engineering design seem to have taken a backseat to thinness recently.

Between the root bug and ones like this, one wonders how many others are out there.
Score: 6 Votes (Like | Disagree)
TrulsZK Avatar
91 months ago
Get an alphanumeric passcode!

1 attempt takes 4 seconds, that means a 16 digit alphanumeric passcode with upper- and lower case, numbers, and two symbols will take up to 64^16=7,922816251e28 seconds which is in practice never. Unless you can run a dictionary attack or something.

With the brute force attempts an alphanumeric passcode is the only solution to stay safe.
[doublepost=1529735909][/doublepost]
3. Pops SIM out of tray
That is exactly why I want eSIM in the iPhone and passcode requirement when switching your phone off + auto restart after force shut down.
Score: 6 Votes (Like | Disagree)

Popular Stories

iphone 16 pro models 1

17 Reasons to Wait for the iPhone 17

Thursday June 12, 2025 8:58 am PDT by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we often get rumored features months ahead of launch. The iPhone 17 series is no different, and we already have a good idea of what to expect from Apple's 2025 smartphone lineup. If you skipped the iPhone...
iOS 26 Screens

Here Are All the iOS 26 Features That Require iPhone 15 Pro or Newer

Thursday June 12, 2025 4:53 am PDT by
With iOS 26, Apple has introduced some major changes to the iPhone experience, headlined by the new Liquid Glass redesign that's available across all compatible devices. However, several of the update's features are exclusive to iPhone 15 Pro and iPhone 16 models, since they rely on Apple Intelligence. The following features are powered by on-device large language models and machine...
apple beta 26 lineup

Apple 'Sherlocked' These Apps at WWDC 2025

Wednesday June 11, 2025 7:14 am PDT by
Apple at WWDC previewed a bunch of new features coming in its updated operating systems, but certain changes will have been met with dismay by third-party developers who already offer apps with equivalent or similar features. In other words, their product has been "sherlocked" by Apple. When Apple creates an app or a feature that has functionality found in a third-party app, it is referred...
iPadOS 26 App Windowing

Apple Explains Why iPads Don't Just Run macOS

Friday June 13, 2025 7:46 am PDT by
iPadOS 26 allows iPads to function much more like Macs, with a new app windowing system, a swipe-down menu bar at the top of the screen, and more. However, Apple has stopped short of allowing iPads to run macOS, and it has now explained why. In an interview this week with Swiss tech journalist Rafael Zeier, Apple's software engineering chief Craig Federighi said that iPadOS 26's new Mac-like ...
iOS 26 on Three iPhones

Hate iOS 26's Liquid Glass Design? Here's How to Tone It Down

Wednesday June 11, 2025 4:22 pm PDT by
iOS 26 features a whole new design material that Apple calls Liquid Glass, with a focus on transparency that lets the content on your display shine through the controls. If you're not a fan of the look, or are having trouble with readability, there is a step that you can take to make things more opaque without entirely losing out on the new look. Apple has multiple Accessibility options that ...
maxresdefault

Everything Apple Announced at WWDC 2025 in 10 Minutes

Monday June 9, 2025 5:21 pm PDT by
At today's WWDC 2025 keynote event, Apple unveiled a new design that will inform the next decade of iOS, iPadOS, and macOS development, so needless to say, it was a busy day. Apple also unveiled a ton of new features for the iPhone, an overhauled Spotlight interface for the Mac, and a ton of updates that make the iPad more like a Mac than ever before. Subscribe to the MacRumors YouTube channel ...
CarPlay Liquid Glass Dark

Apple to Let iPhone Users Watch Videos on CarPlay Screen While Parked

Thursday June 12, 2025 6:16 am PDT by
Apple this week announced that iPhone users will soon be able to watch videos right on the CarPlay screen in supported vehicles. iPhone users will be able to wirelessly stream videos to the CarPlay screen using AirPlay, according to Apple. For safety reasons, video playback will only be available when the vehicle is parked, to prevent distracted driving. The connected iPhone will be able to...
iOS 26 Apple Wallet Boarding Passes

Apple Lists 10 Airlines Set to Offer iOS 26's Upgraded Boarding Passes

Wednesday June 11, 2025 11:28 am PDT by
As we previously reported, iOS 26 enhances Apple Wallet app boarding passes in a few ways. First, the passes now support Live Activities, allowing you to keep track of a flight at a glance on your iPhone's Lock Screen, and in the Dynamic Island on the iPhone 14 Pro and newer. In addition, new shortcuts below the passes provide one-tap access to Apple Maps for airport directions, and to the Find...