A memory corruption issue exists in QuickTime's handling of movie files. Viewing a maliciously crafted movie file may lead to an unexpected application termination or arbitrary code execution. This issue is addressed through improved handling of movie files. For Mac OS X v10.6 systems, this issue is addressed in Mac OS X v10.6.5. Credit to Honggang Ren of Fortinet's FortiGuard Labs, and an anonymous researcher working with TippingPoint's Zero Day Initiative for reporting this issue.