Smart Contract Audit Report
TELE is a new BEP-20 token on the Binance Smart Chain.
For this audit, we reviewed the project team's TeleChat contract at 0xC81d88D694aB25f68e5129b7E73244fA06e08E13 on the Binance Smart Chain Mainnet.
Low findings were identified and the team should consider resolving these issues. In addition, some centralized aspects are present.
Date: November 22nd, 2022.
Updated: December 2nd, 2022 to reflect the project's newly deployed mainnet address.
Finding #1 - TeleChat - LowDescription: The Sell fee is calculated based on the returned getReserves() values of the Pair. This value can be manipulated through the use of a flash loan. However, in the contract's current state, there is no way to borrow TELE, thereby mitigating any current risk of a flash loan attack.
Risk/Impact:If another source of tokens is made available for borrowing, a malicious user can leverage a flash loan to manipulate the reserve amounts in order to yield a 0% sell fee.
Recommendation: The team should implement a Time Weighted Average Price Oracle (TWAP) or use Chainlink for pricing to mitigate the potential price manipulation.
Finding #2 - TeleChat - InformationalDescription: Although the SafeMath library is utilized, the contract is deployed with Solidity v0.8.15 which has built-in overflow checks.
Recommendation: SafeMath could be safely removed to reduce contract size, deployment costs, and gas costs on all transactions that utilize it.
- The total supply of the token is set to 10 million [10,000,000] $TeleChat.
- No public mint or burn functions are present, though the circulating supply can be decreased by sending tokens to the 0x..dead address.
- At the time of writing this report, there are 4 total token holders. The token allocation is as follows:
- 88.1% of the total supply belongs to the owner.
- 8% of the total supply belongs to the team's Nation Receiver wallet.
- 2.4% of the total supply belongs to the team's Team Receiver wallet.
- 1.5% of the total supply belongs to the team's Seed Receiver wallet.
- The contract enforces a maximum sell amount which imposes a limit to the number of tokens that can be sold via Pancakeswap.
- There is a Sell fee charged on all sells via Pancakeswap when the sender is not excluded from fees.
- The Sell fee percentage is calculated based on the returned getAmountOut and getAmountIn values of the TELE and WBNB reserves and the sell-slippage value set by the team.
- The tokens collected through the fee are sent to the 0x00 address.
- As the contract is deployed with Solidity v0.8.0, it is safe from any possible overflows/underflows.
- The contract complies with the BEP-20 token standard.
- The owner can enable/disable the Sell fee at any time.
- The owner can exclude and include accounts from the Sell fee at any time.
- The owner can set the maximum sell amount to any value at any time.
- The owner can exclude and include accounts from the maximum sell amount at any time.
- The owner can set the sell-slippage value to any value at any time.
|Arbitrary Jump/Storage Write||N/A||PASS|
|Centralization of Control||The owner can set the maximum sell amount to any value at any time.||PASS|
|Delegate Call to Untrusted Contract||N/A||PASS|
|Dependence on Predictable Variables||N/A||PASS|
|Flash Loans||The returned getAmountOut and getAmountIn values are used when calculating the Sell fee percentage. A flash loan could be utilized to manipulate the reserve amounts in order to yield a 0% sell fee.||WARNING|
|Improper Authorization Scheme||N/A||PASS|
|Outdated Compiler Version||N/A||PASS|
|Overall Contract Safety||PASS|
($) = payable function # = non-constant function Int = Internal Ext = External Pub = Public + [Lib] Address - [Int] isContract - [Int] sendValue # - [Int] functionCall # - [Int] functionCall # - [Int] functionCallWithValue # - [Int] functionCallWithValue # - [Prv] _functionCallWithValue # + [Lib] SafeMath - [Int] add - [Int] sub - [Int] sub - [Int] mul - [Int] div - [Int] div - [Int] mod - [Int] mod + Context - [Int] _msgSender - [Int] _msgData + Ownable (Context) - [Pub]
# - [Pub] owner - [Pub] renounceOwnership # - modifiers: onlyOwner - [Pub] transferOwnerShip # - modifiers: onlyOwner + [Int] IERC20 - [Ext] totalSupply - [Ext] balanceOf - [Ext] transfer # - [Ext] allowance - [Ext] approve # - [Ext] transferFrom # + [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 # + ERC20 (Context, IERC20) - [Pub] # - [Pub] name - [Pub] symbol - [Pub] decimals - [Pub] totalSupply - [Pub] balanceOf - [Pub] transfer # - [Pub] allowance - [Pub] approve # - [Pub] transferFrom # - [Pub] increaseAllowance # - [Pub] decreaseAllowance # - [Int] _transfer # - [Int] _mint # - [Int] _burn # - [Int] _approve # - [Int] _setupDecimals # - [Int] _beforeTokenTransfer # + TeleChat (ERC20, Ownable) - [Pub] # - modifiers: ERC20 - [Ext] ($) - [Int] _transfer # - [Prv] _checkLps # - [Prv] _getTcWbnbReserves - [Prv] _getAmountOutWbnb - [Prv] _getAmountInTc - [Prv] _getAmountIn - [Prv] _getAmountOut - [Prv] _transferSellStandard # - [Prv] _getSellFees - [Prv] _convertToSellSlippage - [Pub] setMaxSell # - modifiers: onlyOwner - [Pub] excludeFromFees # - modifiers: onlyOwner - [Pub] getExcludeFromFee - [Pub] excludeFromMaxSell # - modifiers: onlyOwner - [Pub] getExcludeFromMaxSell - [Pub] setEnableFee # - modifiers: onlyOwner - [Pub] updateFixSellSlippage # - modifiers: onlyOwner
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What is a Solidity Audit?
Typically, a smart contract audit is a comprehensive review process designed to discover logical errors, security vulnerabilities, and optimization opportunities within code. A Solidity Audit takes this a step further by verifying economic logic to ensure the stability of smart contracts and highlighting privileged functionality to create a report that is easy to understand for developers and community members alike.
How Do I Interpret the Findings?
Each of our Findings will be labeled with a Severity level. We always recommend the team resolve High, Medium, and Low severity findings prior to deploying the code to the mainnet. Here is a breakdown on what each Severity level means for the project:
- High severity indicates that the issue puts a large number of users' funds at risk and has a high probability of exploitation, or the smart contract contains serious logical issues which can prevent the code from operating as intended.
- Medium severity issues are those which place at least some users' funds at risk and has a medium to high probability of exploitation.
- Low severity issues have a relatively minor risk association; these issues have a low probability of occurring or may have a minimal impact.
- Informational issues pose no immediate risk, but inform the project team of opportunities for gas optimizations and following smart contract security best practices.