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 in the parsing of PICT files in QuickTime.qts. While processing data for opcode 0x71 QuickTime trusts a value contained in the file and makes an allocation accordingly. By providing a malicious value this buffer can be undersized and subsequently can be overflowed leading to arbitrary code execution under the context of the user running QuickTime.