An issue was discovered in certain Apple products. iOS before 10.3 is affected. macOS before 10.12.4 is affected. The issue involves the "Kernel" component. It allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.
Apple Security Advisory 2017-03-27-4 - iOS 10.3 is now available and addresses code execution, information disclosure, denial of service, and various other vulnerabilities.