An issue was discovered in certain Apple products. iOS before 10.2 is affected. macOS before 10.12.2 is affected. watchOS before 3.1.3 is affected. The issue involves the "CoreGraphics" component. It allows attackers to cause a denial of service (NULL pointer dereference and application crash) via a crafted font.
https://support.apple.com/HT207487
https://support.apple.com/HT207423
https://support.apple.com/HT207422