Devices running iOS 6 are cancelling calendar appointments sent to distribution lists

This isn't quite right.

The mobile device sends only one message: back to the meeting organizer. It does not send to all other attendees.

Exchange does have a process to automatically handle meeting responses. It is either this process, or the organizer's client program, that are getting confused and are rebroadcasting the cancelation to all other attendees.

Normally, ACLs on the organizer's calendars limit who has permission to make changes within that folder. Hence this message is 'tricking' a process with enough privileges into doing the dirty work. Having these processes accept cancellations from a source unauthorized to take that action is either a server-side bug (more likely, I think) or a client bug in the client used by the organizer. I think it takes two problems to allow this to occur, one on the iOS device and one on the server.

This is not a new issue it happened to me in iOS 5 as well... I think the issue is related to having more than one Exchange profile... Can the folks who are seeing the issue validate wheter they have one or two Exchange Profiles? With the Archive mailbox in Exchange 2010, it is easy now for many people to have two profiles... I found this problem last year because I have accounts on two Exchange Orgs with the same Hosted Provider... The issue presented itself when I declined a meeting invitation from a conference coordinator that came from Google calendars and as I had my gmail account configured, the request not only showed up in my Exchange calendar, but also my gmail calendar... I deleted one of these so I didn't see the duplicate and it sent a cancellation to all 80 or so people on the invite... the issue was that I was then give ownership of their responses as well... when they accepted or decliend the update they got, all of those responsed came to me... on the iPhone, my name was now in the organizers spot... in Outlook, it was still the original organizer...

Yes, I remember this. But it's not what I could see in the Logfiles and the snapshots of the respective Mailboxes.

There was definately no cancellation to the mailbox of the organizer but response-mails to all other invitees.

I am not convinced, that we have to deal with ACL-spoofing but more with an improper synchronisation/matching of data-fields.

By the way, I cannot confirm that the issue is connected to cases with more than one Exchange Profile.

Stay tuned.

"iPhone offers in the calendar app the option to approve or accept the change by clicking an "OK" Button"

I've tried this multiple ways and still havent seen this "OK" button. I have found that if a new date or time is proposed, the event is attached to an email without the new proposed date or time. its essentially the original event that was sent.

Do you have the Premier Support Case number assigned to this issue? Also, has anyone formally opened the case with Apple and if so ID #? I'm seeing the same issue. Thanks in advance.

Here's an interesting article on this:

http://www.tuaw.com/2012/10/04/exchange-ios-meeting-hijack-history-goes-back-wel l-before-ios/

Thanks for this, looks like a bull's-eye...like herpes, it always relapses.😟

We're also running into this issue. Exchange 2003, 8000 users. For our users it seems to take place independently of any user action on the iOS device. Has Apple acknowledged that this is happening and has anyone with Premier Support got any traction on the issue?

We are experiencing same issue on exchange 2003.

User was setup on new iPad and a few hours later it sent out meeting cancellation notice company wide. User advised he did not accept or decline request yet a cancellation notice was sent. Exchange log files confirm his iPad was connected at this time and even references the event cancellation subject name, then the same subject appears on other mailboxes after this.

Apple please assist!

Going over the server's active sync logs indicate multiple IOS devices running different IOS versions connecting to same mailbox. According to timestamp at the time of the offending message both iPads were connecting at times very close to each other. Does anyone else here have the same scenario?

Having the same issue here, running Exchange 2010 SP2 RU2 or 3 can't remember off top of my head. Just got a request from a user where her meetings were canceled by a 3rd party and it appears like others have said that it's a mailformed ICS file coming back to all attendies in the meeting with the cancellation and the Outlook client is processing it as such.

Seems that exchange would block it but I guess not since it's going to all clients. This seems that it would have to be a IOS fix not a Microsoft fix, but Microsoft may be able to block the behavior, but that is going to rely on everyone with Exchange to update their servers and even then these messages will go to the entire distribution groups it sends too so even if the meeting keeps from being canceled you have to hope the clients that are part of the distribution groups don't remove the meetings from the calendars, exchange would have to intercept the message before forwarding on to the others in the groups, and if any individuals outside the exchange org are in the invite list will get cancellations too.

Man what a messy bug, this is going to have to rely on a IOS update and it takes apple forever to release patches and then you have to hope everyone updates their IOS devices to prevent the issue.

Also thanks for all your work on this BishopTJ, please let us know ASAP what you find out!

We're having a user (VP) experiencing this issue today, but in reverse(?!) of what I've read on this board & here http://www.tuaw.com/2012/10/04/exchange-ios-meeting-hijack-history-goes-back-wel l-before-ios/

Our setup:

Exchange 2007 SP3 UR8

User has two iDevices (iPad & iPhone 5), and Laptop w/ Outlook 2010

What happened

User received a calendar invite from an external company (Fortune 500), addressed To: 3 internal users & 3 users of the same company as the meeting organizer. Also CC'd: were 6 other users, same as meeting organizer.

Our user says he was in Outlook and accepted the meeting request. We can see in his mailbox a meeting cancelation went out to all 13 people (original organizer, 3 internal users & 10 users from external company), followed by what looks like a meeting invite from the User to all 13 people, with the user as the organizer.

The meeting cancellation notice shows in the headers

Content-Type: multipart/alternative;

boundary="Apple-Mail-B4E2A3A1-F2E5-450B-AC80-53663AAA15AB"

And the same meeting invitiation now a duplicate invitation but as the User as organizer shows it came from Outlook.

We haven't opened a ticket with Microsoft, or Apple.

I opened a support case today with Apple on this issue and they are fully aware and working on a resolution. I wasn't even asked for serial number or anything, I just mentioned it was an IOS 6 related problem and they knew right away. Maybe if enough people open tickets on the same problem it will get Apple to move quickly on a resolution.

We opened a case with Apple and Microsoft as well. Apple needs to step up to the plate and fix all of these calendar issues. That arrogant stance is not sitting well with Enterprise customers. Fix is Apple!!!