An issue was discovered in certain Apple products. iOS before 11.1 is affected. macOS before 10.13.1 is affected. tvOS before 11.1 is affected. watchOS before 4.1 is affected. The issue involves the "Kernel" component. It allows attackers to monitor arbitrary apps via a crafted app that accesses process information at a high rate.
https://support.apple.com/HT208222
https://support.apple.com/HT208221