Citigroup Warns of Security Flaw in iPhone App

Citigroup Inc. said its free U.S. mobile-banking application for Apple Inc.'s iPhone contained a security flaw and advised its customers to upgrade to a newer version that corrects the problem. In an incident that highlights the growing security challenges around wireless apps, Citi said its iPhone app accidentally saved information -- including account numbers, bill payments and security access codes -- in a hidden file on users' iPhones.