The "Save for Web" selection in QuickTime Player in Apple Mac OS X through 10.6.8 exports HTML documents that contain an http link to a script file, which allows man-in-the-middle attackers to conduct cross-site scripting (XSS) attacks by spoofing the http server during local viewing of an exported document.
Apple Security Advisory 2011-10-26-1 - QuickTime 7.7.1 is now available and addresses memory disclosure, arbitrary code execution, script injection, and various other vulnerabilities.