An issue was discovered in certain Apple products. iOS before 11.2 is affected. macOS before 10.13.2 is affected. tvOS before 11.2 is affected. The issue involves the "Kernel" component. It allows local users to bypass intended memory-read restrictions or cause a denial of service (system crash).
https://www.exploit-db.com/exploits/43521/
https://support.apple.com/HT208334
https://support.apple.com/HT208331