Sanctuary Token

Smart Contract Audit Report

Audit Summary

Sanctuary Token Audit Report Sanctuary Token is a new BEP-20 token on the Binance Smart Chain that is an automatic liquidity providing protocol.

For this audit, we reviewed the project team's Sanctuary contract at 0x4670f3a2A8D35021257cda028c7ae3Cb854C7CaF on the Binance Smart Chain Mainnet.

Audit Findings

Low findings were identified and the team should consider resolving these issues. In addition, some centralized aspects are present.
Date: August 30th, 2023.
Updated: September 18th, 2023 to reflect the contract's newly deployed Mainnet address.

Finding #1 - Sanctuary - Low (Resolved)

Description: In the swapAndLiquify() function, amountBNBCharity will always equal zero as amountBNBMarketing is set to the remainder of the contract's BNB balance before the amountBNBCharity calculation. 
uint256 amountReceived = address(this).balance;

uint256 amountBNBLiquidity = amountReceived.mul(_liquidityShare).div(totalBNBFee).div(2);
uint256 amountBNBDevelopment = amountReceived.mul(_developmentShare).div(totalBNBFee);
uint256 amountBNBMarketing = amountReceived.sub(amountBNBLiquidity).sub(amountBNBDevelopment);
uint256 amountBNBCharity = amountReceived.sub(amountBNBLiquidity).sub(amountBNBDevelopment).sub(amountBNBMarketing);
Risk/Impact: The charityWalletAddress will never be allocated any BNB as intended by the team.
Recommendation: The above calculations should be modified as follows to properly allocate BNB to the respective addresses based on their allocated shares: 
uint256 amountBNBLiquidity = amountReceived.mul(_liquidityShare).div(totalBNBFee).div(2);
uint256 amountBNBDevelopment = amountReceived.mul(_developmentShare).div(totalBNBFee);
uint256 amountBNBMarketing = amountReceived.mul(_marketingShare).div(totalBNBFee);
uint256 amountBNBCharity = amountReceived.sub(amountBNBLiquidity).sub(amountBNBDevelopment).sub(amountBNBMarketing);
Resolution: The team has implemented the above recommendation.

Finding #2 - Sanctuary - Low

Description: The swapAndLiquify() function transfers BNB from the contract to the team's fee addresses using the transfer() function instead of the call() function.
Risk/Impact: The transfer() function uses a hardcoded gas amount of 2300, meaning transactions could run out of gas as the team receives BNB if the receiver is a contract.
Recommendation: The team should use .call.value{...}("") instead as it does not have a gas limitation.
Resolution: The team has not yet addressed this issue.

Finding #3 - Sanctuary - Low

Description: The owner can call the lock() function to temporarily transfer ownership to address(0). Ownership is restored when the unlock() function is invoked after the time duration set by the owner has elapsed; however, _previousOwner is not reset.
Risk/Impact: The unlock() function can be used after ownership has been renounced, thereby restoring ownership to the original owner who initially invoked the lock() function. This capability could be nefariously used to regain ownership after it has been renounced.
Recommendation: The team should modify the unlock() function to set _previousOwner to address(0) at the end of the function or remove the lock functionality from the contract altogether.
Resolution: The team has not yet addressed this issue.

Finding #4 - Sanctuary - Low (Resolved)

Description: The _autoburnShare state variable is included in the _totalDistributionShares calculation upon deployment but is not allocated to any fund.
Risk/Impact: The _totalDistributionShares value is inaccurate on deployment as _autoburnShare is not used in the contract.
Recommendation: As the contract is deployed, the owner can call the setDistributionSettings() function to properly set the contract's shares as _autoburnShare is not included in this function. Alternatively, the team could remove _autoburnShare from the contract altogether or utilize it in a way that fits their intended functionality.
Resolution: The team has removed the _autoburnShare state variable from the contract.

Finding #5 - Sanctuary - Informational (Resolved)

Description: The _buyAutoburnFee and _sellAutoburnFee state variables are redundant as the tokens collected through these fees are not allocated to any fund.
Recommendation: The team should remove _buyAutoburnFee and _sellAutoburnFee from the contract or utilize them in a way that fits their intended functionality. Alternatively, as the contract is deployed, the owner can call the setBuyTaxes() and setSellTaxes() functions to ensure the contract's fees are properly set, as _buyAutoburnFee and _sellAutoburnFee are not included in these functions.
Resolution: The team has removed the _buyAutoburnFee and _sellAutoburnFee state variables from the contract.

Finding #6 - Sanctuary - Informational (Resolved)

Description: The private _takeAutoBurn() function is never called in the contract.
Recommendation: The above function should either be removed to reduce contract size and deployment costs or utilized in a way that fits the project team's intended functionality.
Resolution: The team has removed the _takeAutoBurn() function from the contract.

Finding #7 - Sanctuary - Informational

Description: 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, deployment costs, and gas costs on all transactions that utilize it.

Finding #8 - Sanctuary - Informational

Description: The setBuybackWalletAddress() function incorrectly updates charityWalletAddress rather than buybackWalletAddress.
Recommendation: The setBuybackWalletAddress() function should be modified to update buybackWalletAddress rather than charityWalletAddress.

Contract Overview

  • The total supply of the token is set to 777.78 trillion $SANC [777,777,777,777,777].
  • No mint or burn functions are publicly accessible, though the circulating supply can be decreased by sending tokens to the 0x..dead address.
  • At the time of writing this report, there are 75 total token holders. The token allocation is as follows:

  • 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 a single transaction.
  • The contract enforces a maximum wallet amount that prevents a transfer from occurring if the recipient's token balance will exceed the limit number of tokens (determined by the owner) after the transfer occurs. The team must ensure all created Pair addresses are properly excluded from this restriction.
  • There is a Liquidity fee, Marketing fee, Development fee, Charity fee, and Buyback fee on all buys and sells via Pancakeswap where neither the sender nor the recipient is excluded from fees.
  • The tokens collected through fees are stored in the contract address. The tokens are swapped for BNB for the purpose of funding Pancakeswap liquidity and team wallets 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 caller is not initiating a buy 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 the team lock these newly acquired LP tokens.
  • The tokens collected through the Marketing fee, Development fee, Charity fee, and Buyback fee are swapped for BNB and sent to the team's Marketing wallet, Development wallet, Charity wallet, and Buyback wallet respectively.
  • 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.
Ownership Controls:
  • The owner can set the Liquidity fee, Marketing fee, Development fee, Charity fee, and Buyback fee for both the buy and sell fee structures to any percentage at any time.
  • The owner can exclude and include accounts from transfer fees at any time.
  • The owner can set the maximum transaction amount and maximum wallet amount to any values at any time.
  • The owner can exclude and include accounts from maximum transaction and maximum wallet restrictions at any time.
  • The owner can enable/disable the maximum wallet restriction 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 enable/disable the contract's token swapping limit at any time.
  • The owner can update the contract's Liquidity, Marketing, Development, and Charity fund allocations to any values at any time.
  • The owner can set the Marketing wallet, Development wallet, and Charity wallet to any addresses at any time.
  • The owner can add/remove any address from the Automated Market Maker Pair list at any time.
  • The owner can update the Router address used in the contract at any time.

Audit Results

Vulnerability Category Notes Result
Arbitrary Jump/Storage Write N/A PASS
Centralization of Control
  • The owner can set the Liquidity fee, Marketing fee, Development fee, Charity fee, and Buyback fee for both the buy and sell fee structures to any percentage at any time.
  • The LP tokens generated through automatic liquidity adds are sent to the owner.
 WARNING
Compiler Issues N/A PASS
Delegate Call to Untrusted Contract N/A PASS
Dependence on Predictable Variables N/A PASS
Ether/Token Theft N/A PASS
Flash Loans N/A PASS
Front Running N/A PASS
Improper Events N/A PASS
Improper Authorization Scheme N/A PASS
Integer Over/Underflow N/A PASS
Logical Issues
  • The swapAndLiquify() function transfers BNB from the contract to the team's fee addresses using the transfer() function instead of the call() function.
  • The owner can call the lock() function to temporarily transfer ownership to address(0). Ownership is restored when the unlock() function is invoked after the time duration set by the owner has elapsed; however, _previousOwner is not reset.
 PASS
Oracle Issues N/A PASS
Outdated Compiler Version N/A PASS
Race Conditions N/A PASS
Reentrancy N/A PASS
Signature Issues N/A PASS
Sybil Attack N/A PASS
Unbounded Loops N/A PASS
Unused Code N/A PASS
Overall Contract Safety   PASS

Inheritance Chart

Smart Contract Audit - Inheritance

Function Graph

Smart Contract Audit - Graph

Functions Overview


 ($) = payable function
 # = non-constant function
 
 Int = Internal
 Ext = External
 Pub = Public

 +  Context 
    - [Int] _msgSender
    - [Int] _msgData

 + [Int] IERC20 
    - [Ext] totalSupply
    - [Ext] balanceOf
    - [Ext] transfer #
    - [Ext] allowance
    - [Ext] approve #
    - [Ext] transferFrom #

 + [Lib] SafeMath 
    - [Int] add
    - [Int] sub
    - [Int] sub
    - [Int] mul
    - [Int] div
    - [Int] div
    - [Int] mod
    - [Int] mod

 + [Lib] Address 
    - [Int] isContract
    - [Int] sendValue #
    - [Int] functionCall #
    - [Int] functionCall #
    - [Int] functionCallWithValue #
    - [Int] functionCallWithValue #
    - [Prv] _functionCallWithValue #

 +  Ownable (Context)
    - [Pub]  #
    - [Pub] owner
    - [Pub] waiveOwnership #
       - modifiers: onlyOwner
    - [Pub] transferOwnership #
       - modifiers: onlyOwner
    - [Pub] getUnlockTime
    - [Pub] getTime
    - [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] 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 #

 +  Sanctuary (Context, IERC20, Ownable)
    - [Pub]  #
    - [Pub] name
    - [Pub] symbol
    - [Pub] decimals
    - [Pub] totalSupply
    - [Pub] balanceOf
    - [Pub] allowance
    - [Pub] increaseAllowance #
    - [Pub] decreaseAllowance #
    - [Pub] minimumTokensBeforeSwapAmount
    - [Pub] approve #
    - [Prv] _approve #
    - [Pub] setMarketPairStatus #
       - modifiers: onlyOwner
    - [Ext] setIsTxLimitExempt #
       - modifiers: onlyOwner
    - [Pub] setIsExcludedFromFee #
       - modifiers: onlyOwner
    - [Ext] setBuyTaxes #
       - modifiers: onlyOwner
    - [Ext] setSellTaxes #
       - modifiers: onlyOwner
    - [Ext] setDistributionSettings #
       - modifiers: onlyOwner
    - [Ext] setMaxTxAmount #
       - modifiers: onlyOwner
    - [Ext] enableDisableWalletLimit #
       - modifiers: onlyOwner
    - [Ext] setIsWalletLimitExempt #
       - modifiers: onlyOwner
    - [Ext] setWalletLimit #
       - modifiers: onlyOwner
    - [Ext] setNumTokensBeforeSwap #
       - modifiers: onlyOwner
    - [Ext] setMarketingWalletAddress #
       - modifiers: onlyOwner
    - [Ext] setDevelopmentWalletAddress #
       - modifiers: onlyOwner
    - [Ext] setCharityWalletAddress #
       - modifiers: onlyOwner
    - [Ext] setBuybackWalletAddress #
       - modifiers: onlyOwner
    - [Pub] setSwapAndLiquifyEnabled #
       - modifiers: onlyOwner
    - [Pub] setSwapAndLiquifyByLimitOnly #
       - modifiers: onlyOwner
    - [Pub] getCirculatingSupply
    - [Prv] transferToAddressETH #
    - [Pub] changeRouterVersion #
       - modifiers: onlyOwner
    - [Ext]  ($)
    - [Pub] transfer #
    - [Pub] transferFrom #
    - [Prv] _transfer #
    - [Int] _basicTransfer #
    - [Prv] swapAndLiquify #
       - modifiers: lockTheSwap
    - [Prv] swapTokensForEth #
    - [Prv] addLiquidity #
    - [Int] takeFee #

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Typically, a smart contract audit is a comprehensive review process designed to discover logical errors, security vulnerabilities, and optimization opportunities within code. A SourceHat 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.