Submission Details
Severity:
Zero slippage can result bad trades.
Vulnerability Details
swap function in SmartVaultV3.sol used calculateMinimumAmountOut to calculate slippage parameter.
uint256 minimumAmountOut = calculateMinimumAmountOut(_inToken, _outToken, _amount);
https://github.com/Cyfrin/2023-12-the-standard/blob/91132936cb09ef9bf82f38ab1106346e2ad60f91/contracts/SmartVaultV3.sol#L217
However calculateMinimumAmountOut function can return zero value.
return collateralValueMinusSwapValue >= requiredCollateralValue ?
0 : calculator.eurToToken(getToken(_outTokenSymbol), requiredCollateralValue - collateralValueMinusSwapValue);
}
https://github.com/Cyfrin/2023-12-the-standard/blob/91132936cb09ef9bf82f38ab1106346e2ad60f91/contracts/SmartVaultV3.sol#L210-L211
It means that user can get 0 tokens when swapping.
Impact
It's possible to swap tokens for nothing.
Tools Used
Manual review.
Recommendations
Consider to revert if slippage is zero.
Updates
Lead Judging Commences
hrishibhat over 1 year ago
Submission Judgement Published Reason: Known issue
Assigned finding tags:
Slippage-issue
Prize pool breakdown
Total prize
20,000 USDC
nSLOC
60933 USDC / LOC
17,500 USDC
2,500 USDC
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