Quicktime and iTunes vulnerabilities
Details of a vulnerability in Apple’s Quicktime and iTunes reported at betanews.com. Secunia also has an advisory. It is listed as moderately critical and affects the current version of both quicktime and itunes on Mac or Windows.
It sounds like a specially crafted .mov file could trigger a heap overflow and allow arbitrary code execution.
The current solution is not to open .mov files from untrusted sources. These days ANY program that opens files from outside your control can be susceptible to attacks, make sure to keep track of any relevant updates for your software. At this time there is no update available, hopefully there will be soon.