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   iOS 6.1.2 Fixes Battery-Draining Exchange Bug

   Agen G. N. Schmitz

   Apple has issued [1]iOS 6.1.2 to address a battery drain bug,
   introduced in iOS 6.1, caused by excessive network communication with
   Microsoft's Exchange Server. The problem occurred when syncing an
   Exchange mailbox on a device running iOS 6.1, producing an
   out-of-control polling of calendars and mailboxes on the Exchange
   server that resulted in ramped-up CPU usage and subsequent battery
   drain. The bug was identified by both [2]Apple and Microsoft, the
   latter of whom issued several [3]workaround strategies for Exchange
   administrators until it could be fixed.

   This is the second patch that's been issued to fix a problem introduced
   in the release of iOS 6.1 (see '[4]iOS 6.1 Expands Global LTE Support,'
   28 January 2013), with iOS 6.1.1 released last week to fix cellular
   connectivity problems on the iPhone 4S (see '[5]iOS 6.1.1 for iPhone 4S
   Aims to Fix Cellular Problems,' 11 February 2013). Additionally, iOS
   6.1 introduced a bug that enabled someone to [6]bypass the passcode on
   a locked iPhone, which then provided access to contacts and photos.
   Apple's release notes (well, note, singular) for iOS 6.1.2 don't
   mention a fix for this exploit, and [7]Ars Technica confirms through
   its own testing that the update doesn't patch this security hole.

   The free updates are available through iTunes as a full download (989.5
   MB for the iPhone version and 1.08 GB for the iPad version), though you
   can drastically save on the download size by updating via the
   over-the-air option on your device (go to Settings > General > Software
   Update). The over-the-air delta for the iPhone is 12.8 MB and just 12.5
   MB for the iPad update. The update is free, and it can be applied to
   the iPhone 3GS and later, iPad 2 and later, and fourth-generation iPod
   touch and later.

References

   1. http://support.apple.com/kb/DL1639
   2. http://support.apple.com/kb/TS4532
   3. http://support.microsoft.com/kb/2814847?wa=wsignin1.0
   4. http://tidbits.com/article/13550
   5. http://tidbits.com/article/13526
   6. http://www.macworld.com/article/2028162/exploit-allows-contacts-photos-access-on-a-locked-iphone-5.html
   7. http://arstechnica.com/apple/2013/02/apple-fixes-exchange-but-not-passcode-unlock-bug-with-ios-6-1-2/

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