A memory corruption issue was addressed with improved validation. This issue affected versions prior to iOS 12, macOS Mojave 10.14, tvOS 12, watchOS 5.
https://github.com/szabo-tibor/CVE-2018-4407
https://github.com/Fans0n-Fan/CVE-2018-4407
https://github.com/zeng9t/CVE-2018-4407-iOS-exploit
https://github.com/WyAtu/CVE-2018-4407
https://github.com/s2339956/check_icmp_dos-CVE-2018-4407-
https://support.apple.com/kb/HT209193
https://support.apple.com/kb/HT209139
https://support.apple.com/kb/HT209108
https://support.apple.com/kb/HT209107