Exposure of Sensitive Information to an Unauthorized Actor
Apple iOS before 9 allows attackers to discover the e-mail address of a player via a crafted Game Center app.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.