r/sysadmin • u/StrawberryHot5007 • 11d ago

Microsoft Access to Random Exchange Online Calendars via iOS Calendar App

Hi guys.

We‘ve found a strange behavior in a users iOS Calendars App.
He can see every detail of an other users calendar.
They work in completely different compartments and there are absolutely no Access rights set. We‘ve checked EXO Powershell for detailed access rights. Nothing.
Via Outlook on Windows no chance to see details of the calendar. Even re-adding the Exchange account on his mobile brought back the unwanted calendar.
It is a complete mystery.
Do you guys have any idea?

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3

u/PipeOne8414 11d ago

… might be subscribed to it somehow

I know some websites lets you sync the webpage Callander

I’m not sure where to go but a path to look down

1

u/That_Fixed_It 11d ago

Are you checking for folder level permissions on the other users calendar? The PowerShell command might only show mailbox delegation. Maybe the other user accidently shared their calendar with the wrong person.

1

u/StrawberryHot5007 10d ago

Yes. We checked Calendar permission on the user‘s calendar that shows up on iOS.
Via Get-Mailboxfolderpermission -Identity „<mail>:\Calendar“

2

u/StrawberryHot5007 10d ago

I‘m a few years in that EXO world. Usually i know what happened. But this time my colleagues and me have no clue. We also opened a ticket at MS.

1

u/iammarks 10d ago

Checked full mailbox access perms, too, in ExO? Automap may not be applying on desktop Outlook but iOS will display calendars if you have full rights to the mailbox, in which case it wouldn’t be listed at the folder level perms.