migratePartnerVault() the first vault does not work properly

mediumCode4rena

Lines of code

https://github.com/code-423n4/2023-05-maia/blob/54a45beb1428d85999da3f721f923cbf36ee3d35/src/maia/tokens/ERC4626PartnerManager.sol#L189

Vulnerability details

Impact

In the migratePartnerVault() method, if vaultId == 0 means illegal address, but the id of the vaults starts from 0, resulting in the first vault being mistaken as an illegal vault address

Proof of Concept

In the migratePartnerVault() method, it will determine whether newPartnerVault is legal or not, by vaultId!=0 of vault

The code is as follows:

solidity📋
    function migratePartnerVault(address newPartnerVault) external onlyOwner {
@>      if (factory.vaultIds(IBaseVault(newPartnerVault)) == 0) revert UnrecognizedVault();

        address oldPartnerVault = partnerVault;
        if (oldPartnerVault != address(0)) IBaseVault(oldPartnerVault).clearAll();
        bHermesToken.claimOutstanding();

But when factory adds vault, the index starts from 0, so the id of the first vault is 0

PartnerManagerFactory.addVault()

solidity📋
contract PartnerManagerFactory is Ownable, IPartnerManagerFactory {
    constructor(ERC20 _bHermes, address _owner) {
        _initializeOwner(_owner);
        bHermes = _bHermes;
        partners.push(PartnerManager(address(0)));
    }

    function addVault(IBaseVault newVault) external onlyOwner {
@>      uint256 id = vaults.length;
        vaults.push(newVault);
        vaultIds[newVault] == id;

        emit AddedVault(newVault, id);
    }

The id of the first vault starts from 0, because in constructor does not add address(0) to the vaults similar to partners

So migratePartnerVault() can't be processed for the first vault

Tools Used

Recommended Mitigation Steps

Similar to partners, in the constructor method, a vault with address(0) is added by default.

solidity📋
contract PartnerManagerFactory is Ownable, IPartnerManagerFactory {
    constructor(ERC20 _bHermes, address _owner) {
        _initializeOwner(_owner);
        bHermes = _bHermes;
        partners.push(PartnerManager(address(0)));
+       vaults.push(IBaseVault(address(0)));
    }

Assessed type

Context