macOS Monterey 12.2 and iOS 15.3 Release Candidates Fix Safari Bug That Leaks Browsing Activity

The macOS Monterey 12.2 and iOS 15.3 release candidates that came out today appear to address a Safari bug that could cause your recent browsing history and details about your identity to be leaked to malicious entities.

safari icon blue banner
As shared last week by browser fingerprinting service FingerprintJS, there is an issue with the WebKit implementation of the IndexedDB JavaScript API. Any website that uses IndexedDB can access the names of IndexedDB databases generated by other websites during the same browsing session.

The bug permits a website to spy on other websites that the user visits while Safari is open, and because some websites use user-specific identifiers in their IndexedDB database names, personal information can be gleaned about the user and their browsing habits.

Browsers that use Apple's WebKit engine are impacted, and that includes Safari 15 for Mac and Safari for iOS 15 and iPadOS 15. Some third-party browsers like Chrome are also affected on iOS and iPadOS 15, but the macOS Monterey 12.2, iOS 15.3, and iPadOS 15.3 updates fix the vulnerability.

FingerprintJS constructed a demo website to let users check to see whether they're impacted, and as 9to5Mac notes, after updating to the new software, the website detects no security holes.

The website is designed to tell users details about their Google accounts. On iOS 15.2.1 and macOS Monterey 12.1, we tested and the demo website was able to detect our Google account. After updating to the macOS Monterey 12.2 RC and the iOS 15.3 RC, the demo website no longer detects any data.

Apple earlier this week prepared a fix for the bug and uploaded it to the WebKit page on GitHub, so we knew that Apple was working to address the vulnerability. With the macOS Monterey 12.2 and iOS 15.3 release candidates now available, we could see these updates be made available to the public as soon as next week.

Tag: Safari
Related Forums: iOS 15, macOS Monterey

Popular Stories

iPhone 17 Pro Dark Blue and Orange

iPhone 17 Release Date, Pre-Orders, and What to Expect

Thursday August 28, 2025 4:08 am PDT by
An iPhone 17 announcement is a dead cert for September 2025 – Apple has already sent out invites for an "Awe dropping" event on Tuesday, September 9 at the Apple Park campus in Cupertino, California. The timing follows Apple's trend of introducing new iPhone models annually in the fall. At the event, Apple is expected to unveil its new-generation iPhone 17, an all-new ultra-thin iPhone 17...
iPhone 17 Pro Iridescent Feature 2

iPhone 17 Pro Clear Case Leak Reveals Three Key Changes

Sunday August 31, 2025 1:26 pm PDT by
Apple is expected to unveil the iPhone 17 series on Tuesday, September 9, and last-minute rumors about the devices continue to surface. The latest info comes from a leaker known as Majin Bu, who has shared alleged images of Apple's Clear Case for the iPhone 17 Pro and Pro Max, or at least replicas. Image Credit: @MajinBuOfficial The images show three alleged changes compared to Apple's iP...
xiaomi apple ad india

Apple and Samsung Push Back Against Xiaomi's Bold India Ads

Friday August 29, 2025 4:54 am PDT by
Apple and Samsung have reportedly issued cease-and-desist notices to Xiaomi in India for an ad campaign that directly compares the rivals' devices to Xiaomi's products. The two companies have threatened the Chinese vendor with legal action, calling the ads "disparaging." Ads have appeared in local print media and on social media that take pot shots at the competitors' premium offerings. One...
iOS 18 on iPhone Arrow Down

Apple Preparing iOS 18.7 for iPhones as iOS 26 Release Date Nears

Sunday August 31, 2025 4:35 pm PDT by
Apple is preparing to release iOS 18.7 for compatible iPhone models, according to evidence of the update in the MacRumors visitor logs. We expect iOS 18.7 to be released in September, alongside iOS 26. The update will likely include fixes for security vulnerabilities, but little else. iOS 18.7 will be one of the final updates ever released for the iPhone XS, iPhone XS Max, and iPhone XR,...
iphone 16 pro ghost hand

iPhone 17 Pro: 5 Reasons Not to Upgrade This Year

Monday September 1, 2025 4:35 am PDT by
Apple will launch its new iPhone 17 series this month, and the iPhone 17 Pro models are expected to get a new design for the rear casing and the camera area. But more significant changes to the lineup are not expected until next year, when the iPhone 18 models arrive. If you're thinking of trading in your iPhone for this year's latest, consider the following features rumored to be coming to...

Top Rated Comments

Dave-Z Avatar
47 months ago

As discovered last week ('https://www.macrumors.com/2022/01/16/safari-15-webkit-indexeddb-bug/') by browser fingerprinting service FingerprintJS
It wasn't discovered last week. It was discovered last year, November 2021. It was disclosed to the public last week.


we knew that Apple was working to address the vulnerability in a timely manner
Addressing the issue nearly two months after it having been reported is not timely, especially considering this patch still hasn't reach the public. If the update comes out in one week that will have been two months since Apple first learned about it.
Score: 31 Votes (Like | Disagree)
centauratlas Avatar
47 months ago
"address the vulnerability in a timely manner.".

But is it really timely? Sure, timely since it was made public, but was it timely since they first were informed of it? I'd say no.
Score: 16 Votes (Like | Disagree)
CaTOAGU Avatar
47 months ago
It really does feel a bit silly that we’re still having to wait on OS level updates to fix a bug in a web browser.
Score: 15 Votes (Like | Disagree)
IGI2 Avatar
47 months ago

It wasn't discovered last week. It was discovered last year, November 2021. It was disclosed to the public last week.



Addressing the issue nearly two months after it having been reported is not timely, especially considering this patch still hasn't reach the public. If the update comes out in one week that will have been two months since Apple first learned about it.
But to be fair, Google Project Zero (and others) has a disclosure policy of 90 days.

We know that this is a privacy breach, but still, modern OSs are fairly complex. Getting to know about it, analysis, fixing it, incorporating in all variants, QA testing, and distributing it to all end users across the globe in one time, whether it's iPhone 6s or iPhone 13 Pro Max is still within reasonable "timely" manner.

We know that they had some public pressure; that's why it's even shorter if we count days since it landed in the news.
Score: 9 Votes (Like | Disagree)
beanbaguk Avatar
47 months ago
To all those members complaining about the "timely manner" statement. I would say this is very timely and your complaints indicate you have no experience in software development.

I've been in software development for many years (I am a Head of Product at a software technology company), and patching something isn't just a 5-minute job, even if you know what the issue is and how to fix it.

A small change on an API will impact many, many areas of a product and this means thorough testing is required, and diligence of any related libraries and products.

This is hugely time-consuming and since this product impacts so many platforms, it's not just a case of patching and letting it go into the wild. Especially in this instance, a security audit would have to also be conducted to show the result works, and this would have to be verified by multiple organisations.

Then, the patch has to be tested to ensure it deploys safely and correctly over the air. That update process takes time to implement, manage and check. It then needs checking again, more testing and feedback from users (beta), and devs to ensure they are not experiencing any issues. Again, all this takes time.

I hope this provides some perspective as to how and why these fixes take a little time.

It reminds me of the days when I used to build websites for clients. Talking to an individual who has zero ideas as to the complexities of a solid product is the most infuriating and patience-testing experience as a developer.

Anyway. Two months for a fix like this on this scale is perfectly acceptable.
Score: 8 Votes (Like | Disagree)
Macintosh TV Avatar
47 months ago
Mozilla has security issues that are more than 2 years old and filed in their system. Chrome has outstanding security issues older than this. Folks need to settle down. This stuff happens. It gets fixed. If you're unhappy with the speed at which a browser or OS patches issues, then it may be time to look elsewhere.
Score: 8 Votes (Like | Disagree)