Echo Tech Coin - Smart Contract Audit Report
Echo Tech Coin ($ECOT) is a new BEP-20 token on the Binance Smart Chain that is an automatic liquidity providing protocol that pays out static rewards to holders.
We reviewed the CoinToken contract at 0x7cFfFc84B2Ae51bBCB6fdf90BED564A1543598c1 on the Binance Smart Chain mainnet.
Please ensure trust in the team prior to investing as they have substantial control in the ecosystem.
Date: February 17th, 2022.
Finding #1 - CoinToken - LowDescription: The owner can use the lock() function to temporarily set ownership to address(0). Ownership is restored after the duration of time determined by the owner has passed and they use the unlock() function.
Risk/Impact: The unlock function has the potential to be used after ownership has been set to address(0), which will restore ownership to the original owner that initially created the ownership lock. This can be used in a nefarious way by the project team to restore ownership and change fee structures.
Recommendation: We recommend that the unlock function be modified to set the previous owner variable equal to address(0) at the end of the unlock function to prevent it from being used more than once per lock.
Finding #2 - CoinToken - InformationalDescription: Several functions are declared public, but are never called internally.Recommendation: We recommend declaring these functions external for additional gas savings on each call.
name, symbol, decimals, totalSupply, transfer, allowance, approve, transferFrom, increaseAllowance, decreaseAllowance, isExcludedFromReward, totalFees, deliver, reflectionFromToken, excludeFromReward, excludeFromFee, includeInFee, setMaxTxPercent, setDevWalletAddress, setSwapAndLiquifyEnabled, isExcludedFromFee
Finding #3 - CoinToken - InformationalDescription: Although the SafeMath library is utilized, the contract is deployed with Solidity v0.8.4 which has built-in overflow checks.
Recommendation: SafeMath could be safely removed to reduce contract size and deployment costs.
- The total supply of the token is set to 150 million $ECOT [150,000,000].
- No mint or burn functions exist, though the circulating supply can be decreased by sending tokens to the 0x..dead address.
- At the time of writing this report, there are 5,994 total token holders. The token allocation is as follows:
- 45.29% of the total supply belongs to the owner.
- 10.97% of the total supply belongs to an upgradeable token vesting contract.
- The next five wallet addresses own a cumulative 15.38% of the total supply.
- 1.79% of the total supply is in Pancakeswap liquidity.
- Of that liquidity, 78.43% of the LP tokens are stored in the upgradeable token vesting contract and will fully vest to the team on September 16, 2022.
- 21.53% of the LP tokens belong to the owner.
- There is a Tax fee, Liquidity fee, and Dev fee on all transfers where neither the sender nor the recipient is excluded from fees.
- The tokens collected through the Tax fee are removed from the circulating supply; This serves as a frictionless fee redistribution which automatically benefits all token holders at the time of each transaction.
- The liquidity fee charged during transfers is stored in the contract address. The tokens are swapped for BNB for the purpose of funding Pancakeswap liquidity when the following conditions are met:
- The automatic liquidity add functionality is enabled by the team.
- The threshold number of tokens in the contract address (determined by the owner) has been reached.
- The contract is not currently performing an automatic liquidity add.
- The transfer is not a buying transaction via Pancakeswap.
- Liquidity-adds are automatically performed by selling the tokens collected as fees, pairing the received BNB with the token, and adding it as liquidity to the pair.
- The LP tokens received through this process are sent to the owner. We recommend that the team lock these newly acquired LP tokens.
- The tokens collected from the Dev fee are sent to the team's Dev wallet.
- The contract enforces a maximum transaction amount (determined by the owner) which imposes a limit to the number of tokens that can be transferred during any given transaction.
- As the contract is deployed with Solidity v0.8.4, it is protected from overflows/underflows.
- The contract complies with the BEP-20 token standard.
- The owner can modify the Tax fee, Liquidity fee, and Dev fee to any percentages at any time.
- The owner can exclude and include accounts from transfer fees and reward distribution.
- The owner can update the maximum transaction amount to any value at any time.
- The owner can enable/disable automatic liquidity adds at any time.
- The owner can update the threshold number of tokens needed to trigger an automatic liquidity add to any value at any time.
- The owner can update the team's Dev wallet to any address at any time.
- The owner can update the Pancakeswap Router address at any time.
External Threat Results
|Arbitrary Storage Write||N/A||PASS|
|Centralization of Control||The owner can set each fee percentage up to 100%.||WARNING|
|Delegate Call to Untrusted Contract||N/A||PASS|
|Dependence on Predictable Variables||N/A||PASS|
|State Change External Calls||N/A||PASS|
|User Supplied Assertion||N/A||PASS|
|Critical Solidity Compiler||N/A||PASS|
|Overall Contract Safety||PASS|
($) = payable function # = non-constant function + [Int] IERC20 - [Ext] totalSupply - [Ext] balanceOf - [Ext] transfer # - [Ext] allowance - [Ext] approve # - [Ext] transferFrom # + [Lib] SafeMath - [Int] tryAdd - [Int] trySub - [Int] tryMul - [Int] tryDiv - [Int] tryMod - [Int] add - [Int] sub - [Int] mul - [Int] div - [Int] mod - [Int] sub - [Int] div - [Int] mod + Context - [Int] _msgSender - [Int] _msgData + [Lib] Address - [Int] isContract - [Int] sendValue # - [Int] functionCall # - [Int] functionCall # - [Int] functionCallWithValue # - [Int] functionCallWithValue # - [Int] functionStaticCall - [Int] functionStaticCall - [Int] functionDelegateCall # - [Int] functionDelegateCall # - [Prv] _verifyCallResult + Ownable (Context) - [Pub]
# - [Pub] owner - [Pub] renounceOwnership # - modifiers: onlyOwner - [Pub] transferOwnership # - modifiers: onlyOwner - [Pub] lock # - modifiers: onlyOwner - [Pub] unlock # + [Int] IUniswapV2Factory - [Ext] feeTo - [Ext] feeToSetter - [Ext] getPair - [Ext] allPairs - [Ext] allPairsLength - [Ext] createPair # - [Ext] setFeeTo # - [Ext] setFeeToSetter # + [Int] IUniswapV2Pair - [Ext] name - [Ext] symbol - [Ext] decimals - [Ext] totalSupply - [Ext] balanceOf - [Ext] allowance - [Ext] approve # - [Ext] transfer # - [Ext] transferFrom # - [Ext] DOMAIN_SEPARATOR - [Ext] PERMIT_TYPEHASH - [Ext] nonces - [Ext] permit # - [Ext] MINIMUM_LIQUIDITY - [Ext] factory - [Ext] token0 - [Ext] token1 - [Ext] getReserves - [Ext] price0CumulativeLast - [Ext] price1CumulativeLast - [Ext] kLast - [Ext] mint # - [Ext] burn # - [Ext] swap # - [Ext] skim # - [Ext] sync # - [Ext] initialize # + [Int] IUniswapV2Router01 - [Ext] factory - [Ext] WETH - [Ext] addLiquidity # - [Ext] addLiquidityETH ($) - [Ext] removeLiquidity # - [Ext] removeLiquidityETH # - [Ext] removeLiquidityWithPermit # - [Ext] removeLiquidityETHWithPermit # - [Ext] swapExactTokensForTokens # - [Ext] swapTokensForExactTokens # - [Ext] swapExactETHForTokens ($) - [Ext] swapTokensForExactETH # - [Ext] swapExactTokensForETH # - [Ext] swapETHForExactTokens ($) - [Ext] quote - [Ext] getAmountOut - [Ext] getAmountIn - [Ext] getAmountsOut - [Ext] getAmountsIn + [Int] IUniswapV2Router02 (IUniswapV2Router01) - [Ext] removeLiquidityETHSupportingFeeOnTransferTokens # - [Ext] removeLiquidityETHWithPermitSupportingFeeOnTransferTokens # - [Ext] swapExactTokensForTokensSupportingFeeOnTransferTokens # - [Ext] swapExactETHForTokensSupportingFeeOnTransferTokens ($) - [Ext] swapExactTokensForETHSupportingFeeOnTransferTokens # + CoinToken (Context, IERC20, Ownable) - [Pub] ($) - [Pub] name - [Pub] symbol - [Pub] decimals - [Pub] totalSupply - [Pub] balanceOf - [Pub] transfer # - [Pub] allowance - [Pub] approve # - [Pub] transferFrom # - [Pub] increaseAllowance # - [Pub] decreaseAllowance # - [Pub] isExcludedFromReward - [Pub] totalFees - [Pub] deliver # - [Pub] reflectionFromToken - [Pub] tokenFromReflection - [Pub] excludeFromReward # - modifiers: onlyOwner - [Ext] includeInReward # - modifiers: onlyOwner - [Prv] _transferBothExcluded # - [Pub] excludeFromFee # - modifiers: onlyOwner - [Pub] includeInFee # - modifiers: onlyOwner - [Ext] setTaxFeePercent # - modifiers: onlyOwner - [Ext] setDevFeePercent # - modifiers: onlyOwner - [Ext] setLiquidityFeePercent # - modifiers: onlyOwner - [Pub] setMaxTxPercent # - modifiers: onlyOwner - [Pub] setDevWalletAddress # - modifiers: onlyOwner - [Pub] setSwapAndLiquifyEnabled # - modifiers: onlyOwner - [Ext] ($) - [Prv] _reflectFee # - [Prv] _getValues - [Prv] _getTValues - [Prv] _getRValues - [Prv] _getRate - [Prv] _getCurrentSupply - [Prv] _takeLiquidity # - [Prv] _takeDev # - [Prv] calculateTaxFee - [Prv] calculateDevFee - [Prv] calculateLiquidityFee - [Prv] removeAllFee # - [Prv] restoreAllFee # - [Pub] isExcludedFromFee - [Prv] _approve # - [Prv] _transfer # - [Prv] swapAndLiquify # - modifiers: lockTheSwap - [Prv] swapTokensForEth # - [Prv] addLiquidity # - [Prv] _tokenTransfer # - [Prv] _transferStandard # - [Prv] _transferToExcluded # - [Prv] _transferFromExcluded # - [Ext] setRouterAddress # - modifiers: onlyOwner - [Ext] setNumTokensSellToAddToLiquidity # - modifiers: onlyOwner