PLAY [PlayFlappy] Token

Unable to find manual contract audit (e.g. Certik, PeckShield, Solidity...)

PlayFlappy.swapExactETHForTokens(uint256,address) (contracts/PlayFlappy.sol#634-639) sends eth to arbitrary user
Dangerous calls:
- transferHelper.buy{value: amountIn}(tokenAddress) (contracts/PlayFlappy.sol#638)
Ensure that an arbitrary user cannot withdraw unauthorized funds.

Additional information: link

Reentrancy in PlayFlappy._transfer(address,address,uint256) (contracts/PlayFlappy.sol#426-550):
External calls:
- processFees(contractTokenBalance) (contracts/PlayFlappy.sol#475)
- transferHelper.buy{value: amountIn}(tokenAddress) (contracts/PlayFlappy.sol#638)
- success = IERC20(CAKE).transfer(address(dividendTracker),dividends) (contracts/PlayFlappy.sol#589-592)
- dividendTracker.distributeCAKEDividends(dividends) (contracts/PlayFlappy.sol#595)
- uniswapV2Router.addLiquidityETH{value: halfForEth}(address(this),tokensOut,0,0,address(0),block.timestamp) (contracts/PlayFlappy.sol#606-613)
- uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(amountIn,0,path,address(this),block.timestamp) (contracts/PlayFlappy.sol#624-630)
External calls sending eth:
- processFees(contractTokenBalance) (contracts/PlayFlappy.sol#475)
- transferHelper.buy{value: amountIn}(tokenAddress) (contracts/PlayFlappy.sol#638)
- uniswapV2Router.addLiquidityETH{value: halfForEth}(address(this),tokensOut,0,0,address(0),block.timestamp) (contracts/PlayFlappy.sol#606-613)
- address(_marketingWalletAddress).transfer(ethForMarketing) (contracts/PlayFlappy.sol#574)
- address(_gamingWalletAddress).transfer(ethForGaming) (contracts/PlayFlappy.sol#578)
State variables written after the call(s):
- super._transfer(_from,address(this),fees) (contracts/PlayFlappy.sol#518)
- _balances[sender] = _balances[sender].sub(amount,ERC20: transfer amount exceeds balance) (contracts/ERC20.sol#269-272)
- _balances[recipient] = _balances[recipient].add(amount) (contracts/ERC20.sol#273)
- super._transfer(_from,_to,_amount) (contracts/PlayFlappy.sol#523)
- _balances[sender] = _balances[sender].sub(amount,ERC20: transfer amount exceeds balance) (contracts/ERC20.sol#269-272)
- _balances[recipient] = _balances[recipient].add(amount) (contracts/ERC20.sol#273)
- swapping = false (contracts/PlayFlappy.sol#476)
Apply the check-effects-interactions pattern.

Additional information: link

PlayFlappy._transfer(address,address,uint256) (contracts/PlayFlappy.sol#426-550) uses a dangerous strict equality:
- launchedAt == 0 && _from == owner() && automatedMarketMakerPairs[_to] (contracts/PlayFlappy.sol#439-441)
Don't use strict equality to determine if an account has enough Ether or tokens.

Additional information: link

Combination 1: Reentrancy vulnerabilities + Functions that send Ether to arbitraty destination. Usual for scams. May be justified by some complex mechanics (e.g. rebase, reflections). DYOR & manual audit are advised.

Reentrancy in PlayFlappy.updateDividendTracker(address) (contracts/PlayFlappy.sol#155-178):
External calls:
- newDividendTracker.excludeFromDividends(address(newDividendTracker)) (contracts/PlayFlappy.sol#170)
- newDividendTracker.excludeFromDividends(address(this)) (contracts/PlayFlappy.sol#171)
- newDividendTracker.excludeFromDividends(owner()) (contracts/PlayFlappy.sol#172)
- newDividendTracker.excludeFromDividends(address(uniswapV2Router)) (contracts/PlayFlappy.sol#173)
State variables written after the call(s):
- dividendTracker = newDividendTracker (contracts/PlayFlappy.sol#177)
Apply the check-effects-interactions pattern.

Additional information: link

PlayFlappy._transfer(address,address,uint256).claims (contracts/PlayFlappy.sol#537) is a local variable never initialized
Initialize all the variables. If a variable is meant to be initialized to zero, explicitly set it to zero to improve code readability.

Additional information: link

PlayFlappy.swapAndLiquify(uint256) (contracts/PlayFlappy.sol#600-614) ignores return value by uniswapV2Router.addLiquidityETH{value: halfForEth}(address(this),tokensOut,0,0,address(0),block.timestamp) (contracts/PlayFlappy.sol#606-613)
Ensure that all the return values of the function calls are used.

Additional information: link

DividendPayingToken.accumulativeDividendOf(address)._owner (contracts/DividendPayingToken.sol#140) shadows:
- Ownable._owner (contracts/Ownable.sol#8) (state variable)
Rename the local variables that shadow another component.

Additional information: link

PlayFlappy.setMaxWalletAmount(uint256) (contracts/PlayFlappy.sol#289-295) should emit an event for:
- _maxWalletAmount = amount (contracts/PlayFlappy.sol#294)
Emit an event for critical parameter changes.

Additional information: link

PlayFlappy.updateUniswapV2Router(address)._uniswapV2Pair (contracts/PlayFlappy.sol#187-188) lacks a zero-check on :
- uniswapV2Pair = _uniswapV2Pair (contracts/PlayFlappy.sol#189)
Check that the address is not zero.

Additional information: link

Variable 'PlayFlappy._transfer(address,address,uint256).lastProcessedIndex (contracts/PlayFlappy.sol#538)' in PlayFlappy._transfer(address,address,uint256) (contracts/PlayFlappy.sol#426-550) potentially used before declaration: ProcessedDividendTracker(iterations,claims,lastProcessedIndex,true,gas,tx.origin) (contracts/PlayFlappy.sol#540-547)
Move all variable declarations prior to any usage of the variable, and ensure that reaching a variable declaration does not depend on some conditional if it is used unconditionally.

Additional information: link

Reentrancy in PlayFlappy.updateUniswapV2Router(address) (contracts/PlayFlappy.sol#180-190):
External calls:
- _uniswapV2Pair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(address(this),uniswapV2Router.WETH()) (contracts/PlayFlappy.sol#187-188)
State variables written after the call(s):
- uniswapV2Pair = _uniswapV2Pair (contracts/PlayFlappy.sol#189)
Apply the check-effects-interactions pattern.

Additional information: link

Reentrancy in PlayFlappy.updateDividendTracker(address) (contracts/PlayFlappy.sol#155-178):
External calls:
- newDividendTracker.excludeFromDividends(address(newDividendTracker)) (contracts/PlayFlappy.sol#170)
- newDividendTracker.excludeFromDividends(address(this)) (contracts/PlayFlappy.sol#171)
- newDividendTracker.excludeFromDividends(owner()) (contracts/PlayFlappy.sol#172)
- newDividendTracker.excludeFromDividends(address(uniswapV2Router)) (contracts/PlayFlappy.sol#173)
Event emitted after the call(s):
- UpdateDividendTracker(newAddress,address(dividendTracker)) (contracts/PlayFlappy.sol#175)
Apply the check-effects-interactions pattern.

Additional information: link

PlayFlappyDividendTracker.canAutoClaim(uint256) (contracts/PlayFlappy.sol#794-800) uses timestamp for comparisons
Dangerous comparisons:
- lastClaimTime > block.timestamp (contracts/PlayFlappy.sol#795)
- block.timestamp.sub(lastClaimTime) >= claimWait (contracts/PlayFlappy.sol#799)
Avoid relying on block.timestamp.

Additional information: link

SafeMathInt.mul(int256,int256) (contracts/SafeMathInt.sol#41-48) is never used and should be removed
Remove unused functions.

Additional information: link

Pragma version^0.6.2 (contracts/SafeMathUint.sol#3) allows old versions
Deploy with any of the following Solidity versions: 0.5.16 - 0.5.17, 0.6.11 - 0.6.12, 0.7.5 - 0.7.6 Use a simple pragma version that allows any of these versions. Consider using the latest version of Solidity for testing.

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Parameter PlayFlappyDividendTracker.getAccount(address)._account (contracts/PlayFlappy.sol#725) is not in mixedCase
Follow the Solidity naming convention.

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Redundant expression "this (contracts/Context.sol#21)" inContext (contracts/Context.sol#15-24)
Remove redundant statements if they congest code but offer no value.

Additional information: link

Reentrancy in PlayFlappy.processFees(uint256) (contracts/PlayFlappy.sol#552-584):
External calls:
- address(_marketingWalletAddress).transfer(ethForMarketing) (contracts/PlayFlappy.sol#574)
- address(_gamingWalletAddress).transfer(ethForGaming) (contracts/PlayFlappy.sol#578)
External calls sending eth:
- swapAndSendDividends(ethForDividends) (contracts/PlayFlappy.sol#570)
- transferHelper.buy{value: amountIn}(tokenAddress) (contracts/PlayFlappy.sol#638)
- address(_marketingWalletAddress).transfer(ethForMarketing) (contracts/PlayFlappy.sol#574)
- address(_gamingWalletAddress).transfer(ethForGaming) (contracts/PlayFlappy.sol#578)
- swapAndLiquify(ethForLiquidity) (contracts/PlayFlappy.sol#582)
- transferHelper.buy{value: amountIn}(tokenAddress) (contracts/PlayFlappy.sol#638)
- uniswapV2Router.addLiquidityETH{value: halfForEth}(address(this),tokensOut,0,0,address(0),block.timestamp) (contracts/PlayFlappy.sol#606-613)
State variables written after the call(s):
- swapAndLiquify(ethForLiquidity) (contracts/PlayFlappy.sol#582)
- _allowances[owner][spender] = amount (contracts/ERC20.sol#341)
Event emitted after the call(s):
- Approval(owner,spender,amount) (contracts/ERC20.sol#342)
- swapAndLiquify(ethForLiquidity) (contracts/PlayFlappy.sol#582)
Apply the check-effects-interactions pattern.

Additional information: link

Variable DividendPayingToken._withdrawDividendOfUser(address)._withdrawableDividend (contracts/DividendPayingToken.sol#83) is too similar to PlayFlappyDividendTracker.getAccount(address).withdrawableDividends (contracts/PlayFlappy.sol#732)
Prevent variables from having similar names.

Additional information: link

PlayFlappyDividendTracker.slitherConstructorVariables() (contracts/PlayFlappy.sol#646-890) uses literals with too many digits:
- minimumTokenBalanceForDividends = 200000 * (10 ** 18) (contracts/PlayFlappy.sol#659-660)
Use: Ether suffix, Time suffix, or The scientific notation

Additional information: link

SafeMathInt.MAX_INT256 (contracts/SafeMathInt.sol#36) is never used in SafeMathInt (contracts/SafeMathInt.sol#34-91)
Remove unused state variables.

Additional information: link

PlayFlappyDividendTracker.minimumTokenBalanceForDividends (contracts/PlayFlappy.sol#659-660) should be constant
Add the constant attributes to state variables that never change.

Additional information: link

buy(address) should be declared external:
- PlayFlappyTransferHelper.buy(address) (contracts/PlayFlappyTransferHelper.sol#16-41)
Use the external attribute for functions never called from the contract.

Additional information: link

Average PancakeSwap trading volume, liqudity, number of swaps are extremely low. Token seems to be dead.

Number of Binance Smart Chain (BSC) token holders is low.

Token is deployed only at one blockchain

Token has only one trading pair

Unable to find PancakeSwap trading pair to compute liquidity.

Unable to find PancakeSwap trading pair to compute volume.

Unable to find PancakeSwap trading pair to compute number of swaps.

Unable to find website, listings and other project-related information

Token has no active CoinGecko listing / rank

Token has no active CoinMarketCap listing / rank

Young tokens have high risks of price dump / death