iOS 15.2.1 and iPadOS 15.2.1 Address HomeKit Vulnerability

Apple today released iOS 15.2.1 and iPadOS 15.2.1, minor updates that include an important security fix for a known HomeKit vulnerability that was first discovered last year.

homekit showdown 2 thumb
According to Apple's security support document for the update, it addresses an issue that could cause a maliciously crafted ‌HomeKit‌ name to result in a denial of service, causing iPhones and iPads not to work.

Apple says that it was caused by a resource exhaustion issue that has now been addressed with improved input validation.


The ‌HomeKit‌ bug was first highlighted in January by Bleeping Computer after being discovered by Trevor Spiniolas. Called "doorLock," the vulnerability is executed by changing the name of a ‌HomeKit‌ device to something with over 500,000 characters.

Attempting to load such a large string of characters causes the iOS device to be sent into a denial of service state, and a forced reset is the only way to recover. Resetting the device results in a loss of data unless there is an available backup, and signing back into an affected iCloud account linked to the broken ‌HomeKit‌ device name can re-trigger the bug.

Apple partially fixed the bug in iOS 15.1 by limiting the length of the name that can be set for a ‌HomeKit‌ device or app, but it didn't entirely fix the issue because malicious people exploiting the vulnerability could use Home invitations rather than a device to trigger the attack.

Because this bug could result in data loss at worst and a device reset at best, it's worth updating to the iOS and iPadOS 15.2.1 updates right away.

Related Forum: iOS 15

Popular Stories

Nineth iOS 19 Feature

iOS 19 Beta is a Month Away With These New Features for Your iPhone

Thursday May 8, 2025 7:37 am PDT by
The first iOS 19 beta is just one month away, and there are already many new features and changes that are expected with it. Apple should seed the first iOS 19 beta to developers immediately following the WWDC 2025 keynote, which is scheduled for Monday, June 9. Following beta testing, the update should be released to the general public in September. Below, we recap the key iOS 19 rumors...
Foldable iPhone 2023 Feature Homescreen

Apple's Foldable iPhone Display Tech May Set New Industry Standard

Thursday May 8, 2025 3:29 am PDT by
Apple's upcoming foldable iPhone will feature a new type of display panel developed by Samsung that has never been used in a foldable product, claims a source with links to Apple's supply chain. According to the account yeux1122 on the Korean Naver blog, the foldable iPhone will use a custom display process for which Apple will hold branding trademark rights, and that meets Apple's stringent ...
siri glow

iPhone Users Now Able to Submit Claims in $95 Million Siri Spying Lawsuit

Wednesday May 7, 2025 11:40 am PDT by
If you owned a Siri-compatible device and had an accidental Siri activation between September 17, 2014 and December 31, 2024, you could be eligible for a payment from Apple as part of a class action lawsuit settlement. Apple in January agreed to pay $95 million to settle a class action lawsuit involving Siri spying accusations, and a website to distribute the funds has now been set up and...
iOS 18

Here Are Apple's Full iOS 18.5 Release Notes

Tuesday May 6, 2025 2:17 pm PDT by
Apple today seeded the release candidate version of iOS 18.5 to developers and public beta testers, giving us a look at the final version of the update that will be provided to the public next week. With the release candidate, Apple provided release notes, so we have a more complete look at the new features that are included in the update, including those that weren't found during the beta...
Mayday Calendar

Apple Acquisition Hints at Upgraded Calendar App on iOS 19 or Beyond

Friday May 9, 2025 9:13 am PDT by
Apple acquired Canadian startup Mayday Labs in April 2024, according to a European Commission listing, spotted by French blog MacGeneration. The acquisition had not received widespread attention from tech publications until now. Apple is legally required to report certain acquisitions to the European Commission, under the terms of the EU's Digital Markets Act. Mayday Labs founder Jeremy...
airpods pro purple

Apple's Camera Equipped AirPods and Apple Watch Could Launch as Soon as 2027

Thursday May 8, 2025 10:14 am PDT by
Apple is working on versions of the AirPods and Apple Watch that incorporate a camera, and the devices could be ready to launch sometime around 2027, reports Bloomberg. Apple has developed a chip codenamed "Nevis" that will be used for its camera-equipped Apple Watch, while a chip codenamed "Glennie" will be incorporated into the AirPods. Apple is aiming to have the chips ready "by around...
fortnite apple featured

Epic Games Submits Fortnite to U.S. App Store

Friday May 9, 2025 9:57 am PDT by
As promised, Epic Games today submitted Fortnite to the U.S. App Store, and if approved by Apple, it will mark the first time that the Fortnite app has been available in the United States since 2020. Fortnite will include options to purchase in-app currency from the web rather than through in-app purchase, which is what got the game banned to begin with. This time, though, Apple has been...

Top Rated Comments

hackedmac Avatar
44 months ago
Does this fix the Snapshots not updating on the cameras?
Score: 8 Votes (Like | Disagree)
PBG4 Dude Avatar
44 months ago

Who really would have created a HomeKit device with a name over 500,000 characters? While it's possible, it's INCREDIBLY unlikely.
The problem isn’t that someone could name an object with >500K characters. The problem is Apple code is willing to accept inputs of this length, even when the field has not had the memory allocated to handle a 500K length string.
Score: 7 Votes (Like | Disagree)
Sydnxt Avatar
44 months ago
Wow, no release notes on the software update screen!
Score: 6 Votes (Like | Disagree)
d4cloo Avatar
44 months ago

I'm a heavy critic on how Apple developed HomeKit. I see I'm getting validated today.
I'm mostly annoyed by the user experience. I have a lot of smart equipment, and it's extremely cumbersome and frankly impossible to design a custom screen in Control Center that is laid out exactly according to my preferences.
Score: 6 Votes (Like | Disagree)
Macintosh TV Avatar
44 months ago
Who really would have created a HomeKit device with a name over 500,000 characters? While it's possible, it's INCREDIBLY unlikely.
Score: 5 Votes (Like | Disagree)
doboy Avatar
44 months ago
Seriously, people accept home invitations from randos? Haha.
Score: 4 Votes (Like | Disagree)