This indicates an attack attempt to exploit a Denial of Service Vulnerability in WebKit.
The vulnerability is due to an error in the vulnerable application when handling a maliciously crafted HTML file. A remote attacker may be able to exploit this to cause a denial of service condition on an affected system.
Apple iOS Safari
Apple Mac OS Safari
Denial of Service: Remote attackers can crash vulnerable systems.
Currently we are unaware of any vendor supplied patch or updates available for this issue.