GF_Err moof_AddBox(GF_Box *s, GF_Box *a)
{
	GF_MovieFragmentBox *ptr = (GF_MovieFragmentBox *)s;
	switch (a->type) {
	case GF_ISOM_BOX_TYPE_MFHD:
		if (ptr->mfhd) ERROR_ON_DUPLICATED_BOX(a, ptr)

			ptr->mfhd = (GF_MovieFragmentHeaderBox *) a;
		return GF_OK;
	case GF_ISOM_BOX_TYPE_TRAF:
		return gf_list_add(ptr->TrackList, a);
	case GF_ISOM_BOX_TYPE_PSSH:
	default:
		return gf_isom_box_add_default(s, a);
	}
}

The product reads data past the end, or before the beginning, of the intended buffer.