DO NOT USE THIS CODE. THIS CODE IS USED TO DEMONSTRATE A VULNERABILITY IN A SOLIDITY CODE.

FibonacciBalance.sol

contract FibonacciBalance {
    address public fibonacciLibrary;
    // the current fibonacci number to withdraw
    uint public calculatedFibNumber;
    // the starting fibonacci sequence number
    uint public start = 3;    
    uint public withdrawalCounter;
    // the fibonancci function selector
    bytes4 constant fibSig = bytes4(sha3("setFibonacci(uint256)"));
    
    // constructor - loads the contract with ether
    constructor(address _fibonacciLibrary) public payable {
        fibonacciLibrary = _fibonacciLibrary;
    }
    function withdraw() {
        withdrawalCounter += 1;
        // calculate the fibonacci number for the current withdrawal user
        // this sets calculatedFibNumber
        require(fibonacciLibrary.delegatecall(fibSig, withdrawalCounter));
        msg.sender.transfer(calculatedFibNumber * 1 ether);
    }
    
    // allow users to call fibonacci library functions
    function() public {
        require(fibonacciLibrary.delegatecall(msg.data));
    }
}