This indicates an attack attempt against a Buffer Overflow vulnerability in Apple QuickTime.
The vulnerability is caused by an error when the software handles a malformed "rtsp" URI. It allows a remote attacker to execute arbitrary code via a malicious QTL file.
Apple QuickTime version 7.1.3 and prior.
Apple iTunes version 7.0.2 and prior.
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the patch, available from the website: