This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of Apple Safari's WebKit. 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 how WebKit processes a range object as defined with the DOM level 2 specification. When processing the contents of a range, WebKit will fail to accommodate for manipulation of the DOM due to an event listener. This can lead to code execution under the context of the application.