In iOS before 11.4, iCloud for Windows before 7.5, watchOS before 4.3.1, iTunes before 12.7.5 for Windows, and macOS High Sierra before 10.13.5, an out-of-bounds read was addressed with improved input validation.
https://support.apple.com/HT208853
https://support.apple.com/HT208852
https://support.apple.com/HT208851