A3S protocol

In the contract `A3SWalletFactory` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority. - function `updateBaseMetaURI()`, to update the NFT base URI. - function `updateWhilelistAddress()`, to update the whitelist validation contract. - function `updateFee()`, to update the NFT mint fees. - function `withdrawEther()`, to withdraw ether from this contract. - function `withdrawToken()`, to withdraw `fiatToken` ERC20 tokens from this contract. - function `UUPSUpgradeable.upgradeTo()`, to upgrade this contract to a new contract. - function `UUPSUpgradeable.upgradeToAndCall()`, to upgrade this contract to a new contract and call a function of the new contract. 

In the contract `MerkleWhitelist` the role `_owner` has authority over the functions shown in the diagram below. Any compromise to the `_owner` account may allow the hacker to take advantage of this authority. - function `updateExecutor()`, to update the `executor` address, which has permission to update the Merkle root hash. - function `updateRootHash()`, to update the Merkle root hash and change the whitelist user list. - function `updateFactory()`, to update the `factory` contract address, which has permission to call the `claimWhitelist()` function. - function `updateRound()`, to increase round. If the NFT minting is limited, the whitelisted users can mint one NFT in a new round. - function `updateIsLimited()`, to enable/disable limited NFT minting.  In the contract `MerkleWhitelist` the role `executor` has authority over the functions shown in the diagram below. Any compromise to the `executor` account may allow the hacker to take advantage of this authority. - function `updateRootHash()`, to update the Merkle root hash and change the whitelist user list.  In the contract `MerkleWhitelist` the role `factory` has authority over the functions shown in the diagram below. Any compromise to the `factory` account may allow the hacker to take advantage of this authority. - function `claimWhitelist()`. The `factory` contract will call this function to check if the user has permission to mint NFT. 

`A3SWalletFactory` is an upgradeable contract, the owner can upgrade the contract without the community's commitment. If an attacker compromises the account, he can change the implementation of the contract and drain tokens from the contract.

If `isLimited` is true, the `owner` is on the whitelist, and `round` is zero, the mintable status will be 1. In this case, the user can not mint NFT in the zero round, so the mintable status should be zero. ```solidity=57 if (isLimited) { if (isWhitelisted(owner, proof)) { if (claimedWhitelist[owner] == round) { status = 1; } else { status = 2; } } } else { status = 3; } ```

`public` functions that are never called by the contract could be declared as `external`. `external` functions are more efficient than `public` functions.

There should always be events emitted in the sensitive functions that are controlled by centralization roles.

Addresses should be checked before assignment or external call to make sure they are not zero addresses. ```solidity=28 factory = factoryAddress; ``` - `factoryAddress` is not zero-checked before being used. --- ```solidity=41 (bool success, bytes memory returnData) = payable( address(contractAddress) ).call{value: amount}(payload); ``` - `contractAddress` is not zero-checked before being used. --- ```solidity=133 whilelistAddress = whitelistContract; ``` - `whitelistContract` is not zero-checked before being used. --- ```solidity=144 fiatToken = token; ``` - `token` is not zero-checked before being used. --- ```solidity=27 executor = executorAddress; ``` - `executorAddress` is not zero-checked before being used. --- ```solidity=39 factory = factoryAddress; ``` - `factoryAddress` is not zero-checked before being used.

Nodes process view function call locally, and each node may limit the execution time. If the value of `tokenIdCounter` is very large, the call to view function `walletListOwnerOf()` takes too long and may fail. ```solidity=218 for (; id <= tokenIdCounter.current(); id++) { if (ownerOf(id) == owner) { results[count] = walletOf(id); count++; } } ```

A local variable is shadowing another component defined elsewhere. ```solidity=50 function isMintable(address owner, bytes32[] calldata proof) ``` - Local variable `owner` in `MerkleWhitelist.isMintable` shadows the function `owner` in `Ownable`. --- ```solidity=72 function isWhitelisted(address owner, bytes32[] calldata proof) ``` - Local variable `owner` in `MerkleWhitelist.isWhitelisted` shadows the function `owner` in `Ownable`. --- ```solidity=81 function claimWhitelist(address owner, bytes32[] calldata proof) external { ``` - Local variable `owner` in `MerkleWhitelist.claimWhitelist` shadows the function `owner` in `Ownable`.

The contract is serving as the underlying entity to interact with one or more third-party protocols. The scope of the audit treats third-party entities as black boxes and assumes their functional correctness. However, in the real world, third parties can be compromised and this may lead to lost or stolen assets. ```solidity=37 address public fiatToken; ``` - The contract `A3SWalletFactory` interacts with third party contract with `IERC20Upgradeable` interface via `fiatToken`.