Array index error in the qtdemux_parse_samples function in gst/qtdemux/qtdemux.c in GStreamer Good Plug-ins (aka gst-plugins-good) 0.10.9 through 0.10.11 allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via crafted Sync Sample (aka stss) atom data in a malformed QuickTime media .mov file, related to "mark keyframes."