WASHINGTON (Reuters) – Two key U.S. House of Representatives Democrats on Tuesday asked Apple Inc’s, chief executive, Tim Cook, to answer questions about a privacy flaw in Apple’s group video chat software after a teenager and his mother tried for days to warn the iPhone maker of the bug.

Apple said on Friday it was fixing the issue with FaceTime and said it planned to improve how it handles reports of software bugs. House Energy and Commerce Chairman Frank Pallone and Representative Jan Schakowsky, who chairs a subcommittee overseeing consumer issues, in a letter, asked Cook about when Apple first learned of the security flaw, the extent to which the flaw may have compromised consumers’ privacy, and if “there are other undisclosed bugs that currently exist and have not been addressed.” Apple did not immediately comment to Reuters.