Citi Mobile app allows customers to check their account balances, transfer funds and pay bills from their iPhone. It is one of the most popular finance applications in the Apple App Store with approximately 120,000 users since it was launched in March 2009. Citigroup told the Wall Street Journal that it had no reason to believe that our customers personal information has been accessed or used inappropriately by anyone. However, there will undoubtedly be concerns that if users lost their iPhone the information could be accessed by an identity thief.”]
Source: https://grahamcluley.com/citi-iphone-banking-app-security-flaw/