• by Mark Walsh  @markfwal, January 18, 2010

With AT&T rushing to match lower Verizon Wireless pricing on voice and data plans on Friday, the carrier managed to shift attention away from the recent focus on its network difficulties, especially when it comes to servicing iPhone customers.

That didn't last long. Over the weekend, the AP reported on an unusual technical glitch in AT&T's network allowed a Georgia mother and her two daughters to inadvertenly access the full Facebook accounts of other users when they logged onto Facebook from their mobile phones.

The cross-up was evidently caused by a routing error on AT&T's part, in which the carrier lost track of which users were which and sent the wrong Facebook sites to the wrong phones. In a statement Monday, AT&T said that in a "limited number of instances, a server software connectivity error" resulted in some wireless customers being logged in to the wrong Facebook account. It didn't say exactly how many subscribers were affected.

In response, technical teams from AT&T and Facebook have been working together to add new "security measures" to prevent the problem from reoccuring. As an added step, the companies are disabling the use of subscriber information as way to log into Facebook accounts automatically. That means AT&T customers won't be able to access Facebook using their phone numbers to access the site. They'll have have to use their regular Facebook account ID instead.

Referring apparently to the situation involving the family in Georgia, AT&T said it's aware of an isolated incident affecting an Atlanta customer caused by a "misdirected cookie." AT&T said the issue was resolved with the customer although the carrier acknowledged it was unclear how the cookie was set on the phone.

The AP story Saturday about the security breach suggested misconfigured equipment, poorly written network software or other technical errors" could have led AT&T to mishandle the information going back and forth between its phones and Facebook.

Security experts cited in the article said they were unfamiliar with a similar flaw previously and indicated it could have far-reaching implications for the Internet and PCs as well as mobile phones. For AT&T and Facebook, which both aim to capitalize on the growth of the mobile Web, preventing this type of security flaw is critical to ensuring confidence in their expanding mobile services.

For AT&T in particular, the Facebook glitch won't help what is already a less than stellar reputation for network reliability.