An advisory originally posted on Milw0rm.com states that Apple QuickTime versions 7.2 and 7.3 on Microsoft Windows Vista and Windows XP Pro SP2 are both affected and also Apple’s iTunes because it also contains a QuickTime component, they
may also be at risk, according to a security advisory by the United States Computer Emergency Readiness Team (US-CERT).
From News.com
The security flaw is found in the Real Time Streaming Protocol (RTSP) supported by Apple’s QuickTime Streaming Server and QuickTime player, US-CERT notes. As a result, users who load a malicious RTSP stream via a QuickTime Media Link file or by visiting a malicious Web page, may find their systems compromised. Malicious attackers, for example, could execute arbitrary code from users’ systems or launch a denial-of-service attack.
What to do? Go to Apple Downloads and Download the latest fixes and workarounds also for more solutions you can checkout US-CERT’s Article on Apple QuickTime RTSP Content-Type header stack buffer overflow. Which includes way to prevent these exploits and explanations.