This indicates a possible exploit of a Heap Buffer Overflow vulnerability in Apple Quicktime.
This issue is caused by an error when handling "MOV" files with malformed STSD atom. A remote attacker may be able to exploit this to execute arbitrary code within the context of the application, via a crafted "MOV"file.
Apple Computer QuickTime prior to 7.3
Apple Computer Mac OS X 10.3.9
Apple Computer Mac OS X 10.4.9
Apple Computer Mac OS X 10.5
System Compromise: Remote attackers can gain control of vulnerable systems.
Refer to the vendor's website for suggested workaround.