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 open a malicious file. The specific flaw exists in the handling of movie data encoded using the Cinepak Video Codec. When parsing the data in the MDAT atom, there exists a signedness error which leads to a heap overflow. When this occurs it can be further leveraged to execute arbitrary code under the context of the current user.