10/13/2012 09:29 am ET Updated Dec 13, 2012

ATT iPhone Customers Hit With Massive Data 'Sipping' Bug

It starts innocently enough -- with AT&T customers getting a text that they have used half their data plan. For most users, the initial reaction is,"that's weird." But then, in just a day or so, even casual data users are in 'overage' -- being charged significant fees for data usage that is far from normal.

The bug is the result of an IOS 6 problem that connects the phone to the cellular data network whenever the phone is connected to a WiFi signal.

AT&T message boards are full of confused customers complaining that since they upgraded they are using "tons of data." Wingrider01 wrote: "I upgraded to iOS 6 on the iPhone 5 and ever since my data usage has skyrocketed even though I am on WiFi 75 percent of the time." And jgarriot posted: "I upgraded to iOS 6 on the iPhone 5 and ever since my data usage has skyrocketed."

The bug was first discovered on Verizon, and Apple released a patch to fix the problem. But so far, no AT&T patch has been offered.

Verizon has confirmed to CNN Money that iPhone owners who have been affected by the bug will not be charged for their data overages. So far, AT&T has publicly declined comment, but any user who calls AT&T will find they are very much aware of the bug. "How much credit do you think you'll need?" offered a friendly AT&T phone rep when asked about the bug. AT&T says they have no idea when the fix will be provided from Apple, but in the meantime, just keep calling in and requesting credit for the data overages. AT&T seems more than happy to rebate the overages until Apple gets around to fixing the issue.