erc20 contract KoreaShow bug(CVE-2018-10973)

An integer overflow in the transferMulti function of a smart contractimplementation for KoreaShow, an Ethereum ERC20 token, allows attackers toaccomplish an unauthorized increase of digital assets via crafted _valueparameters.“`Let`s see where this issue is:function transferMulti(address[] _to, uint256[] _value) public returns(uint256 amount){ require(_to.length == _value.length); uint8 len = uint8(_to.length); for(uint8 j; j<len; j++){ amount += _value[j]; <——here, crafted _value can makeamount overflow } require(balanceOf[msg.sender] >= amount); for(uint8 i; i<len; i++){ address _toI = _to[i]; uint256 _valueI = _value[i]; balanceOf[_toI] += _valueI; balanceOf[msg.sender] -= _valueI; Transfer(msg.sender, _toI, _valueI); } }“`