GF_Err padb_Size(GF_Box *s)
{
	GF_PaddingBitsBox *ptr = (GF_PaddingBitsBox *)s;
	ptr->size += 4;
	if (ptr->SampleCount) ptr->size += (ptr->SampleCount + 1) / 2;

	return GF_OK;
}

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