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 Apple Lossless Audio Codec streams. While parsing the sample description for the 'alac' codec an integer wrap can occur that results in the allocation of a memory buffer that is smaller than intended. When Quicktime writes to this buffer it causes a memory corruption that can lead to remote code execution under the context of the current user.