Valinity Audit

In the contract `BEP20` the role `_owner` has authority over the functions shown in the diagram below.  In the contract `MFCToken` the role `_adminAgents` has authority over the functions shown in the diagram below.  In the contract `MFCToken` the role `_backendAgents` has authority over the functions shown in the diagram below.  In the contract `MFCToken` the role `_mfcExchangeCap` has authority over the functions shown in the diagram below.  In the contract `BUSDT` the role `_adminGovAgents` has authority over the functions shown in the diagram below.  In the contract `BUSDT` the role `_governanceAddress` has authority over the functions shown in the diagram below.  In the contract `BUSDT` the role `_mfcExchangeFloor` has authority over the functions shown in the diagram below.  In the contract `RegistrarMigrator` the role `_adminAgents` has authority over the functions shown in the diagram below.  In the contract `Registrar` the role `_adminAgents` has authority over the functions shown in the diagram below.  In the contract `MultiSig` the role `executor` has authority over the functions shown in the diagram below.  In the contract `Ownable` the role `_owner` has authority over the functions shown in the diagram below.  In the contract `AccessControl` the role `account` has authority over the functions shown in the diagram below.  In the contract `BackendAgent` the role `_backendAdminAgents` has authority over the functions shown in the diagram below.  In the contract `WithdrawAgent` the role `_withdrawAdminAgents` has authority over the functions shown in the diagram below.  In the contract `WithdrawAgent` the role `_withdrawAgents` has authority over the functions shown in the diagram below.  Any compromise to the privileged accounts may allow the hacker to take advantage of this authority and switch owners, withdraw tokens, and modify critical configurations of the contracts.

In the contract `exchange/MFCExchange.sol`, `exchange/MFCExchangeFloor.sol`, `exchange/MFCExchangeCap.sol`, `governance/MFCGovernance.sol`, `MFCCollateralLoan.sol`, `MFCTradingLicense.sol`, `token/MFCToken.sol` and `treasury/BUSDT.sol`, the role `_registrar` has authority over the following functions: - updateAddresses() In the contract `lib/access/AccessControl.sol`, the role `adminRole` has authority over the following functions: - grantRole() - revokeRole() In the contract `token/MFCToken.sol`, the role `MINTER_ROLE` has authority over the following functions: - mint() - grantOwnerRole() - grantMinterRole() - grantWhitelisterRole() - revokeOwnerRole() - revokeMinterRole() - revokeWhitelisterRole() - whitelistUser() - whitelistUserBatch() - whitelistAgent() - revokeWhitelistedUser() - revokeWhitelistedAgent() Any compromise to the privileged accounts may allow the hacker to take advantage of this authority and switch owners, withdraw tokens, and modify critical configurations of the contracts.

In the contract `MFCCollateralLoan` the role `_adminGovAgents` has authority over the functions shown in the diagram below.  In the contract `MFCCollateralLoan` the role `_backendAdminAgents` has authority over the functions shown in the diagram below.  In the contract `MFCCollateralLoan` the role `_backendAgents` has authority over the functions shown in the diagram below.  In the contract `MFCCollateralLoan` the role `_deployer` has authority over the functions shown in the diagram below.  In the contract `MFCGovernance` the role `_adminAgents` has authority over the functions shown in the diagram below.  In the contract `MFCExchange` the role `_backendAgents` has authority over the functions shown in the diagram below.  In the contract `MFCExchangeCap` the role `_adminGovAgents` has authority over the functions shown in the diagram below.  In the contract `MFCExchangeCap` the role `_backendAgents` has authority over the functions shown in the diagram below.  In the contract `MFCExchangeCap` the role `_governanceAddress` has authority over the functions shown in the diagram below.  In the contract `MFCExchangeFloor` the role `_deployer` has authority over the functions shown in the diagram below.  In the contract `MFCTradingLicense` the role `_adminAgents` has authority over the functions shown in the diagram below.  In the contract `MFCTradingLicense` the role `_adminGovAgents` has authority over the functions shown in the diagram below.  In the contract `MFCTradingLicense` the role `_deployer` has authority over the functions shown in the diagram below.  In the contract `MFCTradingLicense` the role `_governanceAddress` has authority over the functions shown in the diagram below.  Any compromise to the privileged accounts may allow the hacker to take advantage of this authority and switch owners, withdraw tokens, and modify critical configurations of the contracts.

```solidity=115 function _getPrice() private view returns (uint256) { uint256 mfcCirculation = _mfc.getMfcCirculation(); uint256 busdBalance = _busdt.getBusdtValue(); if (busdBalance == 0) { return 0; } if (mfcCirculation > 0) { return MULTIPLIER * mfcCirculation / busdBalance; } else { return _initialPrice; } } ``` In contract `MFCExchangeFloor`, function `_getPrice()` returns the price of MFC that equals `MULTIPLIER * mfcCirculation / busdBalance` (when `mfcCirculation` > 0). Which means MFC is backed by BUSD in the treasury. So the following functions in contract `MFCToken` can be used to manipulate the price of MFC by changing `mfcCirculation`: - `setMfcCirculation()` - `airdropTokens()` The role `_adminAgents` can call `setMfcCirculation()` and set `_mfcCirculation` to any value. The role `_bankendAgents` can call `airdropTokens()` and mint tokens to addresses without increasing MFC's circulation by setting `updateCirculation` to false.

Addresses should be checked before assignment or external call to make sure they are not zero addresses. ```solidity=163 _busdComptrollerAddress = busdComptrollerAddress_; ``` - `busdComptrollerAddress_` is not zero-checked before being used. --- ```solidity=70 _busdAddress = busdAddress_; ``` - `busdAddress_` is not zero-checked before being used. --- ```solidity=71 _busdComptrollerAddress = busdComptrollerAddress_; ``` - `busdComptrollerAddress_` is not zero-checked before being used. --- ```solidity=56 _busdComptrollerAddress = busdComptrollerAddress_; ``` - `busdComptrollerAddress_` is not zero-checked before being used.