This indicates an attack attempt against a Memory Corruption vulnerability in Apple QuickTime.
The vulnerability is caused by a validation error when the vulnerable software parses certain properties in a QuickTime TeXML file. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted TeXML file.
Apple Computer QuickTime prior to 7.7.4
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.