Users might sell NFT or fractional tokens for 0

[code423n4]

Lines of code

https://github.com/code-423n4/2022-12-caviar/blob/0212f9dc3b6a418803dbfacda0e340e059b8aae2/src/Pair.sol#L406

Vulnerability details

Impact

Users might sell NFT or fractional tokens for 0 base token.

Proof of Concept

The return value of function Pair.sol#sellQuote may be 0.

function sellQuote(uint256 inputAmount) public view returns (uint256) {
    uint256 inputAmountWithFee = inputAmount * 997;
    return (inputAmountWithFee * baseTokenReserves()) / ((fractionalTokenReserves() * 1000) + inputAmountWithFee);
}

This will result in the user calling Pair.sol#sell lose the inputAmount of fractional tokens, because 0 base token will send to the user if minOutputAmount = 0.

Tools Used

Manual

Recommended Mitigation Steps

I recommend to revert the Pair.sol#sell if outputAmount is 0

[Shungy]

Technically the dup of #424 .
However the actual issue is described in #436

[c4-judge]

berndartmueller marked the issue as duplicate of #243

[c4-judge]

berndartmueller marked the issue as satisfactory