# Duplicated slippage check in SyrupUserActions Low/Info · Three Sigma · Permissionless lending · 23rd August, 2024 Finding 3S-SY-N02 of the Maple Syrup security review. - Protocol: https://maple.finance/ - Report: /reports/maple-finance-syrup - Source: https://github.com/0xsimao/audits/blob/main/Three%20Sigma/2024-08-23-maple-finance-syrup.pdf --- ### Description SyrupUserActions::_swap() checks the slippage at the end `require(amountOut_ >= minAmountOut_, "SUA:S:INSUFFICIENT_AMOUNT_OUT");`. When the asset out is USDC, it double checks the slippage in SyrupUserActions::_swapDaiForUsdc() as `require(usdcOut_ >= minUsdcOut_, "SUA:SDU:INSUFFICIENT_AMOUNT_OUT");`. ### Recommendation There is no need to check the slippage in SyrupUserActions::_swapDaiForUsdc(). --- Related findings: - [`SyrupBitcoinRouter::requestRedeem()` could also check if the asset picked to redeem has liquidity](https://0xsimao.com/findings/maple-finance-iii-syrup-bitcoin-redeem-picked): Maple Withdrawal Queue - [`ManagedLeveragedVault::donateCollateral()` is missing a slippage check](https://0xsimao.com/findings/beraborrow-i-managed-donate-collateral-slippage): Beraborrow Managed Dens - [Unnecessary user balance check in _withdrawRequest()](https://0xsimao.com/findings/glacier-unnecessary-balance-withdraw-request): Glacier - [`BaseTOFT.sol`: `retrieveFromStrategy` can be used to manipulate other user's positions due to absent approval check](https://0xsimao.com/findings/tapioca-dao-retrieve-manipulate-absent-approval): Tapioca DAO