This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Quicktime. 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 Sample Duration values in the Time-To-Sample atoms. This value is used in the calculation of a loop counter. If this counter is too big it will result in a heap overflow that can cause remote code execution under the context of the current user.