Home Cyber Security News Researcher Found ‘doorLock’ DoS Bug In Apple HomeKit

Researcher Found ‘doorLock’ DoS Bug In Apple HomeKit

by Abeerah Hashim
Apple HomeKit DoS bug

A researcher has recently disclosed a DoS bug in Apple HomeKit which he coined ‘doorLock.’ Exploiting this bug renders the HomeKit devices non-functional as it continues to trigger even after rebooting. This bug likely affects all iOS devices from iOS 14.7 to iOS 15.2. However, it has still not received a patch from Apple.

Apple HomeKit ‘doorLock’ DoS Flaw

Security researcher Trevor Spiniolas has shared a detailed post about a denial-of-service vulnerability affecting Apple users. Identified as ‘doorLock,’ this DoS bug affects many iPhones and iPads, thereby putting a considerable userbase at risk.

Briefly, the issue resides in how the operating system renders the name of an Apple HomeKit device. Setting up a long device name (such as a 500,000-character string that the researcher tested) will trigger a Dos state on the affected iOS device.

This vulnerability typically exists in iOS versions earlier than iOS 15 because Apple since introduced a character limit on the name. However, this bug also affects iOS 15 devices since it will occur if a vulnerable device shares HomeKit data with a non-vulnerable device.

What’s worse is that the bug doesn’t resolve with a reboot. Instead, it will keep triggering right after the user signs in to the iCloud account linked with the HomeKit device.

The researcher demonstrated the exploit in this video.

The following video shows how an adversary can trigger the bug via fake invitations. This exploit can even trick users with no HomeKit device.

Spiniolas has also shared an app on GitHub that triggers this bug. (Use it for testing purposes only).

Patch Still Awaited

After discovering the vulnerability, the researcher contacted Apple to report the matter in August 2021. Unfortunately, while the Cupertino giant acknowledged the bug, they didn’t exhibit promptness to address it.

According to the researcher, Apple kept delaying the fix, eventually promising it for “early 2022”. However, given the flaw’s seriousness upon exploitation, the researcher went for public disclosure to alert users. As stated in his post,

This bug poses a significant risk to the data of iOS users, but the public can protect themselves from the worst of its effects by disabling Home devices in control center in order to protect local data.

While a definitive solution to this denial-of-service bug is yet to arrive, the researcher recommends the affected users to recover their device via the DFU Mode, setting it up as normal without signing in to the iCloud account and then logging into the iCloud via Settings. Users can then choose to disable “Home” immediately to render the device and iCloud account function again.

Whereas, for those who still want to access Home Data, the researcher advises the following step after signing into their iCloud account via Settings.

-Press the back button and then press Control Center settings again to reload the page, and repeat this until a setting labeled “Show Home Controls” is visible. Immediately disable the setting.
-Install the test application and run it with a short string to rename all associated Home devices.

Let us know your thoughts in the comments.

You may also like

Latest Hacking News

Privacy Preference Center


The __cfduid cookie is used to identify individual clients behind a shared IP address and apply security settings on a per-client basis.

cookie_notice_accepted and gdpr[allowed_cookies] are used to identify the choices made from the user regarding cookie consent.

For example, if a visitor is in a coffee shop where there may be several infected machines, but the specific visitor's machine is trusted (for example, because they completed a challenge within your Challenge Passage period), the cookie allows Cloudflare to identify that client and not challenge them again. It does not correspond to any user ID in your web application, and does not store any personally identifiable information.

__cfduid, cookie_notice_accepted, gdpr[allowed_cookies]


DoubleClick by Google refers to the DoubleClick Digital Marketing platform which is a separate division within Google. This is Google’s most advanced advertising tools set, which includes five interconnected platform components.

DoubleClick Campaign Manager: the ad-serving platform, called an Ad Server, that delivers ads to your customers and measures all online advertising, even across screens and channels.

DoubleClick Bid Manager – the programmatic bidding platform for bidding on high-quality ad inventory from more than 47 ad marketplaces including Google Display Network.

DoubleClick Ad Exchange: the world’s largest ad marketplace for purchasing display, video, mobile, Search and even Facebook inventory.

DoubleClick Search: is more powerful than AdWords and used for purchasing search ads across Google, Yahoo, and Bing.

DoubleClick Creative Solutions: for designing, delivering and measuring rich media (video) ads, interactive and expandable ads.



The _ga is asssociated with Google Universal Analytics - which is a significant update to Google's more commonly used analytics service. This cookie is used to distinguish unique users by assigning a randomly generated number as a client identifier. It is included in each page request in a site and used to calculate visitor, session and campaign data for the sites analytics reports. By default it is set to expire after 2 years, although this is customisable by website owners.

The _gat global object is used to create and retrieve tracker objects, from which all other methods are invoked. Therefore the methods in this list should be run only off a tracker object created using the _gat global variable. All other methods should be called using the _gaq global object for asynchronous tracking.

_gid works as a user navigates between web pages, they can use the gtag.js tagging library to record information about the page the user has seen (for example, the page's URL) in Google Analytics. The gtag.js tagging library uses HTTP Cookies to "remember" the user's previous interactions with the web pages.

_ga, _gat, _gid