This indicates an attack attempt to exploit a Memory Corruption vulnerability in WebKit, a component of Apple Safari.
The vulnerability is due to an error when the vulnerable software handles a maliciously crafted web page. An attacker can exploit this by tricking an unsuspecting user into visiting a malicious webpage and execute arbitrary code within the context of the application.
WebKit in iOS before 12.1.3
WebKit in tvOS before 12.1.2
WebKit in Safari before 12.0.3
WebKit in iTunes for Windows before 12.9.3
WebKit in iCloud for Windows before 7.10
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.