A smartphone app expected to be widely used by athletes and other visitors to next month’s Beijing Winter Games has glaring security flaws that could expose sensitive data to eavesdropping, according to a report published on Tuesday. Citizen Lab, an internet watchdog group, said in its report that the MY2022 app has serious encryption flaws that would leave users’ sensitive data — and any other data communicated through it — vulnerable to hacking. Other important user data in the app was not encrypted at all, the report found. That means the data could be read by Chinese ISPs or telecom...