An issue was discovered in certain Apple products. iOS before 10.1 is affected. macOS before 10.12.1 is affected. tvOS before 10.0.1 is affected. watchOS before 3.1 is affected. The issue involves the "AppleMobileFileIntegrity" component, which allows remote attackers to spoof signed code by using a matching team ID.
https://support.apple.com/HT207275
https://support.apple.com/HT207271
https://support.apple.com/HT207270