An issue was discovered in certain Apple products. iOS before 11.2 is affected. macOS before 10.13.2 is affected. iCloud before 7.2 on Windows is affected. iTunes before 12.7.2 on Windows is affected. tvOS before 11.2 is affected. watchOS before 4.2 is affected. The issue involves the "CFNetwork Session" component. It allows attackers to execute arbitrary code in a privileged context or cause a denial of service (memory corruption) via a crafted app.