This indicates an attack attempt against a buffer overflow vulnerability in Apple Quicktime Pictureviewer.
The vulnerability is caused by an error when the vulnerable software handles a specially crafted JP2 file. It allows remote attackers to execute arbitrary code or cause a denial of service (application crash) via a crafted jp2 file.
Mac OS X v10.5.8, Mac OS X Server v10.5.8
Denial of service
Apply the patch supplied by the vendor: