NEW YORK ( TheStreet) -- Citigroup ( C) has found a security flaw in one of its key mobile banking apps designed for Apple's ( AAPL) iPhone, but denied there's any data breach. "During a recent review, we discovered that our U.S. Citi Mobile iPhone banking app was accidentally saving information related to customer accounts in a hidden file on their iPhones," explained a Citi spokeswoman in an email to TheStreet. "This information may also have been saved on their computer if they had been synchronizing their iPhone with their computer via iTunes."
Citi has no reason to believe that customers' personal information has been accessed inappropriately as a result of the glitch, according to the spokeswoman. "There has been no data breach," she said. Locking down data on wireless devices presents an ongoing challenge for businesses, particularly with devices like smartphones handling ever more sophisticated and sensitive information. Firms also are also confronted with an unflattering media feeding frenzy whenever they are linked with a data breach. Earlier this year, Apple iPad partner AT&T ( T) hit the headlines following a data breach that exposed the email addresses of iPad subscribers. The Citi spokeswoman told TheStreet that an update has been released for the compromised banking app, which corrects the problem. "This update deletes any Citi Mobile information that may have been saved to their iPhone or computer, and it eliminates the possibility that this will occur in the future," she added. "We are communicating with our customers who downloaded the app to tell them about the update." Citi, however, says that only its Mobile iPhone banking app is affected by the security glitch. The company's iPhone app for credit card customers -- and its other mobile services -- haven't been impacted by the problem. The company also added that "a relatively small number" of customers were impacted by the security problem. Apple has not yet responded to TheStreet's request for comment on this story. -- Reported by James Rogers in New York Follow James Rogers on Twitter.