This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Mac OSX. 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 parsing of a dfont file. When processing a malformed dfont file, a specified value is parsed from the file and passed to the memmove API call which can cause memory corruption. A remote attacker can use this to execute remote code under the context of the user.