AirDropper

## Description `Deploy.s.sol` script provide the wrong value causing eligible address can not claim when the contract are deployed using the script. ## Vulnerability Details There are mismatch in value of merkle tree and merkle proof provided in `Deploy.s.sol` and `MerkleAirdropTest.t.sol` as the latter provided the correct value but the `Deploy.s.sol` script provide the wrong value causing eligible address can not claim when the contract are deployed using the script. NOTE: this assume the value of `s_zkSyncUSDC` used in `Deploy.s.sol` are already corrected using `0x1d17CBcF0D6D143135aE902365D2E5e2A16538D4` otherwise it would revert and not showing `MerkleAirdrop__InvalidProof` error. If we run `yarn run makeMerkle` the following value would be returned: ```bash Merkle Root: 0xf69aaa25bd4dd10deb2ccd8235266f7cc815f6e9d539e9f4d47cae16e0c36a05 Proof for address: 0x20F41376c713072937eb02Be70ee1eD0D639966C with amount: 25000000000000000000: [ '0x4fd31fee0e75780cd67704fbc43caee70fddcaa43631e2e1bc9fb233fada2394', '0xc88d18957ad6849229355580c1bde5de3ae3b78024db2e6c2a9ad674f7b59f84' ] ``` the Merkle Root value `0xf69aaa25bd4dd10deb2ccd8235266f7cc815f6e9d539e9f4d47cae16e0c36a05` are used in the `Deploy.s.sol` script: ```javascript @> bytes32 public s_merkleRoot = 0xf69aaa25bd4dd10deb2ccd8235266f7cc815f6e9d539e9f4d47cae16e0c36a05; // 4 users, 25 USDC each uint256 public s_amountToAirdrop = 4 * (25 * 1e6); ``` this is problematic because the intended value for every claim is `25 USDC` or `25 * 1e6` because USDC decimal is 6 instead of 18, and the above Merkle Root value are intended for `25 * 1e18`. the `claim` function cannot be called successfully because the contract only held `s_amountToAirdrop = 4 * (25 * 1e6)` USDC and user cannot claim `25 * 1e18` as this is wrong value. <details><summary>PoC</summary> Add your zksync rpc url `ZKSYNC_MAINNET_RPC_URL` to `.env` file. Add this helper code to `Deploy.s.sol` so our test can capture the address of `MerkleAirdrop` and `IERC20` contract: ```diff - function run() public { + function run() public returns (MerkleAirdrop, IERC20) { vm.startBroadcast(); MerkleAirdrop airdrop = deployMerkleDropper(s_merkleRoot, IERC20(s_zkSyncUSDC)); // Send USDC -> Merkle Air Dropper IERC20(0x1d17CBcF0D6D143135aE902365D2E5e2A16538D4).transfer(address(airdrop), s_amountToAirdrop); vm.stopBroadcast(); + // add helper + return (airdrop, IERC20(s_zkSyncUSDC)); } ``` Add `MerkleAirdropDeployScriptTest.t.sol` to `test` folder. `MerkleAirdropDeployScriptTest.t.sol`: ```javascript // SPDX-License-Identifier: MIT pragma solidity 0.8.24; import { MerkleAirdrop, IERC20 } from "../src/MerkleAirdrop.sol"; import { AirdropToken } from "./mocks/AirdropToken.sol"; import { Deploy } from "script/Deploy.s.sol"; import { Test } from "forge-std/Test.sol"; import { console } from "forge-std/Test.sol"; contract MerkleAirdropTest is Test, Deploy { MerkleAirdrop public airdrop; IERC20 public tokenIERC20; AirdropToken public token; uint256 amountToCollect = (25 * 1e6); // 25.000000 uint256 amountToSend = amountToCollect * 4; address collectorOne = 0x20F41376c713072937eb02Be70ee1eD0D639966C; // using proof from makeMerkle.js bytes32 proofOne = 0x4fd31fee0e75780cd67704fbc43caee70fddcaa43631e2e1bc9fb233fada2394; bytes32 proofTwo = 0xc88d18957ad6849229355580c1bde5de3ae3b78024db2e6c2a9ad674f7b59f84; bytes32[] public proof = [proofOne, proofTwo]; function setUp() public { // assume deployer have enough USDC balance, we use deal address correctUSDCAddress = 0x1d17CBcF0D6D143135aE902365D2E5e2A16538D4; deal(address(IERC20(correctUSDCAddress)), address(msg.sender), amountToSend); console.log("USDC before:", IERC20(correctUSDCAddress).balanceOf(address(msg.sender))); // running the Deploy.s.sol script (airdrop, tokenIERC20) = Deploy.run(); console.log("USDC after:", IERC20(correctUSDCAddress).balanceOf(address(msg.sender))); } function testPOCUsingDeployScriptContractBrokenBecauseWrongMerkleRoot() public { // assume the correct USDC address are used in deploying MerkleAirdrop.sol uint256 startingBalance = tokenIERC20.balanceOf(collectorOne); vm.deal(collectorOne, airdrop.getFee()); vm.startPrank(collectorOne); airdrop.claim{ value: airdrop.getFee() }(collectorOne, amountToCollect, proof); vm.stopPrank(); uint256 endingBalance = tokenIERC20.balanceOf(collectorOne); assertEq(endingBalance - startingBalance, amountToCollect); } ``` after that run the following `forge test --zksync --fork-url $ZKSYNC_MAINNET_RPC_URL --mt testPOCUsingDeployScriptContractBrokenBecauseWrongMerkleRoot` the test will FAIL: ```bash Failing tests: Encountered 1 failing test in test/MerkleAirdropDeployScriptTest.t.sol:MerkleAirdropTest [FAIL. Reason: MerkleAirdrop__InvalidProof()] testPOCUsingDeployScriptContractBrokenBecauseWrongMerkleRoot() (gas: 32340) ``` </details> ## Impact user cannot claim the airdrop ## Recommendations Changing the correct Merkle Root can solve this problem. <details><summary>Code</summary> Using modified `makeMerkle.js` we can generate the correct value: ```diff . . . /*////////////////////////////////////////////////////////////// INPUTS //////////////////////////////////////////////////////////////*/ - const amount = (25 * 1e18).toString(); + const amount = (25 * 1e6).toString(); const userToGetProofOf = "0x20F41376c713072937eb02Be70ee1eD0D639966C"; // (1) const values = [ [userToGetProofOf, amount], ["0x277D26a45Add5775F21256159F089769892CEa5B", amount], ["0x0c8Ca207e27a1a8224D1b602bf856479b03319e7", amount], ["0xf6dBa02C01AF48Cf926579F77C9f874Ca640D91D", amount], ]; /*////////////////////////////////////////////////////////////// PROCESS //////////////////////////////////////////////////////////////*/ // (2) const tree = StandardMerkleTree.of(values, ["address", "uint256"]); // (3) console.log("Merkle Root:", tree.root); // (4) for (const [i, v] of tree.entries()) { // if (v[0] === userToGetProofOf) { // (3) const proof = tree.getProof(i); + console.log(`Proof for address: ${v} with amount: ${amount}:\n`, proof); - console.log(`Proof for address: ${userToGetProofOf} with amount: ${amount}:\n`, proof); - } } . . . ``` after that run `yarn run makeMerkle` and the following should returned: ```bash Merkle Root: 0x3b2e22da63ae414086bec9c9da6b685f790c6fab200c7918f2879f08793d77bd Proof for address: 0x20F41376c713072937eb02Be70ee1eD0D639966C,25000000 with amount: 25000000: [ '0x32cee63464b09930b5c3f59f955c86694a4c640a03aa57e6f743d8a3ca5c8838', '0x8ff683185668cbe035a18fccec4080d7a0331bb1bbc532324f40501de5e8ea5c' ] Proof for address: 0x277D26a45Add5775F21256159F089769892CEa5B,25000000 with amount: 25000000: [ '0x2683f462a4457349d6d7ef62d4208ef42c89c2cff9543cd8292d9269d832c3e8', '0xdcad361f30c4a5b102a90b4ec310ffd75c577ccdff1c678adb20a6f02e923366' ] Proof for address: 0x0c8Ca207e27a1a8224D1b602bf856479b03319e7,25000000 with amount: 25000000: [ '0xee1cda884ead2c9f34338f48263e7edd6e5f35bf4f09c9c0930d995911004eed', '0x8ff683185668cbe035a18fccec4080d7a0331bb1bbc532324f40501de5e8ea5c' ] Proof for address: 0xf6dBa02C01AF48Cf926579F77C9f874Ca640D91D,25000000 with amount: 25000000: [ '0x1e6784ff835523401f4db6e3ab48fa5bdf523a46a5bc0410a5639d837352b194', '0xdcad361f30c4a5b102a90b4ec310ffd75c577ccdff1c678adb20a6f02e923366' ] ``` using the correct value above, we should change the `Deploy.s.sol` value of `s_merkleRoot`: `Deploy.s.sol`: ```diff - bytes32 public s_merkleRoot = 0xf69aaa25bd4dd10deb2ccd8235266f7cc815f6e9d539e9f4d47cae16e0c36a05; + bytes32 public s_merkleRoot = 0x3b2e22da63ae414086bec9c9da6b685f790c6fab200c7918f2879f08793d77bd; // 4 users, 25 USDC each uint256 public s_amountToAirdrop = 4 * (25 * 1e6); ``` after that add the following code to `MerkleAirdropDeployScriptTest.t.sol` that we already created beforehand. `MerkleAirdropDeployScriptTest.t.sol`: ```javascript function testUsingDeployScriptContractCorrectMerkleRoot() public { // assume the correct USDC address are used in deploying MerkleAirdrop.sol // using the correctly generated merkleProof bytes32[] memory correctProofs = new bytes32[](8); correctProofs[0] = 0x32cee63464b09930b5c3f59f955c86694a4c640a03aa57e6f743d8a3ca5c8838; correctProofs[1] = 0x8ff683185668cbe035a18fccec4080d7a0331bb1bbc532324f40501de5e8ea5c; correctProofs[2] = 0x2683f462a4457349d6d7ef62d4208ef42c89c2cff9543cd8292d9269d832c3e8; correctProofs[3] = 0xdcad361f30c4a5b102a90b4ec310ffd75c577ccdff1c678adb20a6f02e923366; correctProofs[4] = 0xee1cda884ead2c9f34338f48263e7edd6e5f35bf4f09c9c0930d995911004eed; correctProofs[5] = 0x8ff683185668cbe035a18fccec4080d7a0331bb1bbc532324f40501de5e8ea5c; correctProofs[6] = 0x1e6784ff835523401f4db6e3ab48fa5bdf523a46a5bc0410a5639d837352b194; correctProofs[7] = 0xdcad361f30c4a5b102a90b4ec310ffd75c577ccdff1c678adb20a6f02e923366; // list of eligible addresses address[4] memory eligibleAddress = [ 0x20F41376c713072937eb02Be70ee1eD0D639966C, 0x277D26a45Add5775F21256159F089769892CEa5B, 0x0c8Ca207e27a1a8224D1b602bf856479b03319e7, 0xf6dBa02C01AF48Cf926579F77C9f874Ca640D91D ]; for (uint256 i = 0; i < eligibleAddress.length; ++i) { uint256 startingBalance = tokenIERC20.balanceOf(eligibleAddress[i]); vm.deal(eligibleAddress[i], airdrop.getFee()); // get corresponding proof for address i bytes32[] memory proofs = new bytes32[](2); proofs[0] = correctProofs[i * 2]; proofs[1] = correctProofs[i * 2 + 1]; vm.startPrank(eligibleAddress[i]); airdrop.claim{ value: airdrop.getFee() }(eligibleAddress[i], amountToCollect, proofs); vm.stopPrank(); uint256 endingBalance = tokenIERC20.balanceOf(eligibleAddress[i]); assertEq(endingBalance - startingBalance, amountToCollect); } } ``` then run the following command `forge test --zksync --fork-url $ZKSYNC_MAINNET_RPC_URL --mt testUsingDeployScriptContractCorrectMerkleRoot` the test result PASS: ```bash Ran 1 test for test/MerkleAirdropDeployScriptTest.t.sol:MerkleAirdropTest [PASS] testUsingDeployScriptContractCorrectMerkleRoot() (gas: 63544) Suite result: ok. 1 passed; 0 failed; 0 skipped; finished in 76.19s (23.89s CPU time) ``` </details>