The sws_init_context function in libswscale/utils.c in FFmpeg before 2.7.2 does not initialize certain pixbuf data structures, which allows remote attackers to cause a denial of service (segmentation violation) or possibly have unspecified other impact via crafted video data.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.