User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.
The specific flaw exists within the way Quicktime handles invalid values in the Sync Sample Atom. Due to a signed compare instead of an unsigned compare it is possible to corrupt the Sample Atom Table. Values from this table are later used to populate a heap buffer and the corrupted value causes a heap overflow. This can result in remote code execution under the context of the current user.
Patch Availability:
Apple has issued an update to correct this vulnerability. More details can be found at: http://support.apple.com/kb/HT4826
