News Stay informed about the latest enterprise technology news and product updates.

Apple iOS 6.1 Exchange 2010 bug hits transaction logs hard

A problem in the latest iPhone and iPad operating system generates an endless loop of transaction logs that can slow Exchange 2010 servers to a crawl.

Admins await an Apple fix to an iOS 6.1 Exchange bug that zaps server resources and knocks out mobile email access.

The iOS 6.1 bug generates an abnormally high amount of transaction logs when an iPhone or iPad user syncs a mailbox using Exchange ActiveSync. It can also drain memory and CPU, degrading performance and eventually disconnecting the device from the server.

Microsoft and Apple have both acknowledged the iOS 6.1 bug, which affects Exchange Server 2010 Service Pack 1 and higher, as well as Office 365's Exchange Online. Problems appear to occur when a user responds to a single instance of a recurring calendar invite.


Apple has released iOS 6.1.2 in an effort to fix this bug.

"I hope Apple will realize they need to spend more time on dev before an update is pushed out," said Steven Barnes, a U.K.-based Microsoft systems developer and Exchange admin. "I would certainly advise users on not updating their devices as soon as they come out."

Apple said it has identified a fix and will issue an update, without providing a timetable. In the meantime, some IT pros are being proactive.

Steve Goodman, an Exchange MVP and IT architect with U.K.-based Phoenix IT Group, tried to spread the word about the iOS 6.1 Exchange 2010 bug.

"I reached out to customers earlier this week and got colleagues to do the same," he said. "Fingers crossed that the customers are OK."

Goodman then wrote a PowerShell script that identifies any iOS devices in an Exchange 2010 environment and lists their OS versions in a .csv file. It also warns users with older iOS versions not to upgrade to 6.1 -- or if they have, to not respond to meeting requests.

How to avoid the iOS 6.1 bug

After identifying iOS 6.1 devices, an administrator has several options to combat the problem.

"We have literally seen all sorts of approaches," said Michael Van Horenbeeck, a technology consultant with Belgium-based Xylos Corp. "Some block iOS 6.1. Others isolate iOS 6.1 users in a separate database and turn on circular logging. And others implement throttling policies, though with mixed results."

Until Apple issues a fix, Microsoft suggests throttling or blocking iOS 6.1 devices, or instructing users to remove and re-add their Exchange accounts from their devices. Apple recommends that users turn their Exchange calendars off, wait 10 seconds and then turn them back on.

Barnes has had to block some of his organization's 3,000 iOS 6.1 device owners from using Exchange ActiveSync, which "has obviously not gone down very well with users," he said.

Apple released iOS 6.1, a relatively minor update, on Jan. 28. Specific adoption figures are not available, but as of this week, iOS 6.1 accounted for 65% of all iPhone and iPad Web traffic, according to online advertising firm Chitika.

The iOS 6.1 Exchange bug is not the only problem IT administrators have to worry about with the new operating system. A security vulnerability in the iPhone's lock screen could also allow unauthorized users to access the information stored on devices.

Let us know what you think about the story; email Site Editor Matt Gervais.

Dig Deeper on Outlook management

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

Has the iOS 6.1 Exchange bug made you reconsider allowing iOS devices in your organization?