32 lines
1.0 KiB
Solidity
32 lines
1.0 KiB
Solidity
/*
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* @source: https://consensys.github.io/smart-contract-best-practices/known_attacks/
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* @author: consensys
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* @vulnerable_at_lines: 28
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*/
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pragma solidity ^0.4.0;
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contract Reentrancy_bonus{
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// INSECURE
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mapping (address => uint) private userBalances;
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mapping (address => bool) private claimedBonus;
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mapping (address => uint) private rewardsForA;
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function withdrawReward(address recipient) public {
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uint amountToWithdraw = rewardsForA[recipient];
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rewardsForA[recipient] = 0;
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(bool success, ) = recipient.call.value(amountToWithdraw)("");
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require(success);
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}
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function getFirstWithdrawalBonus(address recipient) public {
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require(!claimedBonus[recipient]); // Each recipient should only be able to claim the bonus once
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rewardsForA[recipient] += 100;
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// <yes> <report> REENTRANCY
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withdrawReward(recipient); // At this point, the caller will be able to execute getFirstWithdrawalBonus again.
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claimedBonus[recipient] = true;
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}
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}
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