This indicates an attempt to exploit a Memory Corruption vulnerability in Apple WebKit.
The vulnerability is due to an error when the vulnerable software attempts to handles maliciously crafted web page. An attacker may exploit this vulnerability by sending a specially crafted web page.
iOS prior to 12
tvOS prior to 12
Safari prior to 12
iTunes for Windows prior to 12.9
iCloud for Windows prior to 7.7
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply patches or fixes from the vendor, available from the website: