Exposing iCloud user’s Name, phone numbers, and email addresses.

Hi There,

Renganathan Here, I’m an Ethical Hacker & a Security researcher.

This writeup is shared publicly with the permission of the Apple Product Security Team.

This write-up is about a misconfiguration that I found on iCloud and how I could have accessed the iCloud user’s name, phone number, and email address.

I’ve submitted only one report to Apple till now but It was not a valid one.

After seeing one of my mentors, Hemant Patidar was awarded $$$$ for finding a vulnerability on apple id, I thought should give it a try to apple again :)

I started with iCloud this time instead of starting with apple.com and subdomain enumerations and other stuff.

I’m not an Apple user, I didn’t know the features and functions so was manually exploring them. Then I clicked upon notes and saw something like the one below.

So there’s a link for the iCloud notes which I can share with people.

The link looked something like the one below:

https://www.icloud.com/notes/neVeRgoNNagiVEyouuP

so just like another bug hunter, I was curious to access others’ notes.

I used the below Google Dorks to enumerate all the notes.

site:icloud.com/notes/*

The notes link were crawled only because they were shared publicly, else Google can’t crawl them.

But that doesn’t stop there I need to gain access to others’ notes.

but a few of them gave me this 404 error.

But they returned with a verification requirement

I clicked on verify,

BOOM! (The most expected word LOL)

That just showed me who’s the owner of the notes by exposing the email id.

Again a few of them showed me the owner’s phone number

By opening the link in the private window it showed me the name of the owner

I tried to get a copy of the verification link by modifying the API request but it was not vulnerable. So I reported this as the owner’s details were exposed, my bug was accepted, and I was credited to the apple hall of Fame.

TimeLine:

June 2, 2021 - Reported

June 16, 2021 - Accepted & patch was implemented against crawling the links.

- Completely fixed.

February, 2022 - got listed in their hall of fame.

Thanks for reading :)
Stay Safe.

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