Axiemon Token Security Audit

2.2 No excluded accounts – unused code.

Severity: note.

Description:

The variables in lines 701-702 is declared but never initialized and there are no functions to initialize them.

    mapping (address => bool) private _isExcluded;
    address[] private _excluded;

Therefore contract could not have excluded from rewards addresses, and numbers of functions and its part are unused:

1. 1. Part of code in function balanceOf (line 791)
   2. Function isExcludedFromReward (lines 825-827)
   3. Part of code in function deliver (line 835)
   4. Part of code in function _takeLiquidity (lines 951-952)
   5. Part of code in function _tokenTransfer (lines 1101-1109)
   6. Function _transferToExcluded (lines 1126-1144)
   7. Function _transferFromExcluded (lines 1136-1144)
   8. Function _transferBothExcluded (lines 860-869)
   9. Part of code in function _getCurrentSupply (lines 938-943).

   Recommendation:

   To increase readability and reduce deployment cost the unused code should be removed.

   2.3 ERC20 Complines – transfer 0 value should be allowed

   Severity: low.

   Description:

   Due ERC20 standard: Transfers of 0 values MUST be treated as normal transfers and fire the Transfer event.

   Recommendation:

   Remove require(amount > 0, "Transfer amount must be greater than zero"); (line 1001).

   2.4 Unused variable mintedByDxsale

   Severity: note.

   Description:

   The variable mintedByDxsale (line 708) was declared but never used.

   Recommendation:

   To increase readability and reduce deployment cost the unused code should be removed.

   2.5 Owner privileges

   Severity: owner privileges.

   Description:

   Contract owner has right to:

   1. Exclude/include any account from/in fee, using functions excludeFromFee (lines 871-873) and includeInFee (lines 875-877).
   2. Change tax fee in range from 0 to maxTaxFee percent, using function setTaxFeePercent (lines 879-878).
   3. Change liquidity fee in range from 0 to maxLiqFee percent, using function setLiquidityFeePercent (lines 884-887).
   4. Change maximal amount per transaction in range from minMxTxPercentage to 100 percent of total supply, using function setMaxTxPercent (lines 889-894).
   5. Enable or disable adding liquidity to pool, using function setSwapAndLiquifyEnabled (lines 896-899).
   6. Enable or disable all fees and transaction amount limit, using functions disableFees (lines 1146-1154) and enableFees (lines 1156-1161).

   3. Security practice

   •  Open-source contact.
   •  The contract should pass a bug bounty after the completion of the security audit.
   •  Public testing.
   •  Automated anomaly detection systems. – NOT IMPLEMENTED. A simple anomaly detection algorithm is recommended to be implemented to detect behavior that is atypical compared to normal for this contract. For instance, the contract must halt deposits in case a large amount is being withdrawn in a short period of time until the owner or the community of the contract approves further operations.
   •  Multisig owner account.
   •  Standard ERC20-related issues. – NOT IMPLEMENTED. It is known that every contract can potentially receive an unintended ERC20-token deposit without the ability to reject it even if the contract is not intended to receive or hold tokens. As a result, it is recommended to implement a function that will allow extracting any arbitrary number of tokens from the contract.
   •  Crosschain address collisions. ETH, ETC, CLO, etc. It is possible that a transaction can be sent to the address of your contract at another chain (as a result of a user mistake or some software fault). It is recommended that you deploy a “mock contract” that would allow you to withdraw any tokens from that address or prevent any funds deposits. Note that you can reject transactions of native token deposited, but you can not reject the deposits of ERC20 tokens. You can use this source code as a mock contract: extractor contract source code. The address of a new contract deployed using CREATE (0xf0) opcode is assigned following this scheme keccak256(rlp([sender, nonce])). Therefore you need to use the same address that was originally used at the main chain to deploy the mock contract at a transaction with the nonce that matches that on the original chain. Example: If you have deployed your main contract with address 0x010101 at your 2021th transaction then you need to increase your nonce of 0x010101 address to 2020 at the chain where your mock contract will be deployed. Then you can deploy your mock contract with your 2021th transaction, and it will receive the same address as your mainnet contract.