The Federal Trade Commission says the mobile apps of movie ticket seller Fandango and credit report provider Credit Karma may have exposed millions of users' sensitive personal information, including credit card data and social security numbers.

The FTC said Friday that the companies failed to properly secure their apps for several years, potentially exposing information users sent or received through the apps.

Fandango and Credit Karma fixed the security issue last year. The companies say they are not aware of any individual's information being stolen. The FTC says that would be difficult to trace.

Fandango, owned by cable provider Comcast Corp., and Credit Karma agreed to settle the FTC's charges.