An issue was discovered in certain Apple products. iOS before 10.3 is affected. macOS before 10.12.4 is affected. tvOS before 10.2 is affected. watchOS before 3.2 is affected. The issue involves symlink mishandling in the "libarchive" component. It allows local users to change arbitrary directory permissions via unspecified vectors.
https://support.apple.com/HT207617
https://support.apple.com/HT207615
https://support.apple.com/HT207602
https://support.apple.com/HT207601