#solidity
Rulesets (2)
Ruleset for smart contract security, contributed by Decurity (https://www.decurity.io/).
Rules (49)
semgrepTo guarantee arguments type safety it is recommended to use `abi.encodeCall` instead of `abi.encodeWithSelector`.
semgrepBy demanding that the receiver of the owner permissions actively accept via a contract call of its own, `Ownable2Step` and `Ownable2StepUpgradeable` prevent the contract ownership from accidentally being transferred to an address that cannot handle it.
semgrepCaching the array length outside a loop saves reading it on each iteration, as long as the array's length is not changed during the loop.
semgrep<x> += <y> costs more gas than <x> = <x> + <y> for state variables.
semgrepUninitialized variables are assigned with the types default value. Explicitly initializing a variable with its default value costs unnecessary gas.
semgrepConsider swapping variables using `($VAR1, $VAR2) = ($VAR2, $VAR1)` to save gas
semgrepConsider making costructor payable to save gas.
semgrepReplace state variable reads and writes within loops with local variable reads and writes.
semgrepA lot of times there is no risk that the loop counter can overflow. Using Solidity's unchecked block saves the overflow checks.
semgrepConsider using custom errors as they are more gas efficient while allowing developers to describe the error in detail using NatSpec.
semgrepUsing multiple require statements is cheaper than using && multiple check combinations. There are more advantages, such as easier to read code and better coverage reports.
semgrepUsing nested is cheaper than using && multiple check combinations. There are more advantages, such as easier to read code and better coverage reports.
semgrepConsider using the prefix decrement expression whenever the return value is not needed. The prefix decrement expression is cheaper in terms of gas.
semgrepConsider using the prefix increment expression whenever the return value is not needed. The prefix increment expression is cheaper in terms of gas.
semgrepShortening revert strings to fit in 32 bytes will decrease gas costs for deployment and gas costs when the revert condition has been met.
semgrepContract can be destructed by anyone in $FUNC
semgrepAn attacker may perform call() to an arbitrary address with controlled calldata
semgrepmsg.sender is not being used when calling erc20.transferFrom. Example - Alice approves this contract to spend her ERC20 tokens. Bob can call function 'a' and specify Alice's address as the from parameter in transferFrom, allowing him to transfer Alice's tokens to himself.
semgrep$VAULT.getPoolTokens() call on a Balancer pool is not protected from the read-only reentrancy.
semgrep$VAR.getRate() call on a Balancer pool is not protected from the read-only reentrancy.
semgrepPossible arithmetic underflow
semgrepPrice oracle can be manipulated via flashloan
semgrepFunction borrowFresh() in Compound performs state update after doTransferOut()
semgrepFunction sweepToken is allowed to be called by anyone
semgrep$POOL.get_virtual_price() call on a Curve pool is not protected from the read-only reentrancy.
semgrepAn attacker may perform delegatecall() to an arbitrary address.
semgrepabi.encodePacked hash collision with variable length arguments in $F()
semgrepAnyone can burn tokens of other accounts
semgrepCustom ERC20 implementation exposes _transfer() as public
semgrepERC677 callAfterTransfer() reentrancy
semgrepCustom ERC721 implementation lacks access control checks in _transfer()
semgrepERC721 onERC721Received() reentrancy
semgrepERC777 tokensReceived() reentrancy
semgrepUniswapV3 adapter implemented incorrect extraction of path parameters
semgrepblockhash(block.number) and blockhash(block.number + N) always returns 0.
semgrepKeep3rV2.current() call has high data freshness, but it has low security, an exploiter simply needs to manipulate 2 data points to be able to impact the feed.
semgrep$F with constant msg.value can be called multiple times
semgrepThe code must not contain any of Unicode Direction Control Characters
semgrepNo slippage check in a Uniswap v2/v3 trade
semgrepPotential signature malleability in $F
semgrepOracle price data can be submitted by anyone
semgrepProxy declares a state var that may override a storage slot of the implementation
semgreptransferFrom() can steal allowance of other accounts
semgrepsetMultipleAllowances() is missing onlyOwner modifier
semgrepOracle update is not restricted in $F()
semgrepA specially crafted calldata may be used to impersonate other accounts
semgrepParameter "from" is checked at incorrect position in "_allowances" mapping
semgrepUniswap callback is not protected
semgrepUnrestricted transferOwnership