Kuiper contest - ye0lde's results

Handle

ye0lde

Vulnerability details

Impact

Gas savings

Proof of Concept

"> 0" is used in the following locations: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L68 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L77 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L93 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L110 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L291

https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Factory.sol#L53

Tools Used

Visual Studio Code, Remix

Recommended Mitigation Steps

Change "> 0" to "!=0" for small gas savings.

Handle

ye0lde

Vulnerability details

Impact

A variable is being assigned its default value in the constructor which is unnecessary. Removing the assignment will save gas when deploying.

Proof of Concept

https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Factory.sol#L22

Tools Used

Visual Studio Code, Remix

Recommended Mitigation Steps

Remove line #22

Handle

ye0lde

Vulnerability details

Impact

Gas savings and code clarity

Proof of Concept

Below are several occurrences of comparison with literal boolean values of true or false: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Auction.sol#L37

https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L92 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L259

Tools Used

Visual Studio Code, Remix

Recommended Mitigation Steps

Use the compared expression itself in place of comparison with a boolean literal. The expression can be replaced as is when the expression is expected to evaluate to true and negation can be used when the expression is expected to have a false value.

Handle

ye0lde

Vulnerability details

Impact

Reducing redundant code and state variable references can reduce gas usage and improve code clarity.

Proof of Concept

The changePublisher function: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L157-L173

I suggest this refactoring:

    function changePublisher(address newPublisher) onlyPublisher public override {
        require(newPublisher != address(0));

        if (pendingPublisher.publisher != address(0) && pendingPublisher.publisher == newPublisher) {
            require(block.timestamp >= pendingPublisher.timestamp + TIMELOCK_DURATION);
            pendingPublisher.publisher = address(0);
            emit ChangedPublisher(publisher = newPublisher);  
        } else {
            pendingPublisher.timestamp = block.timestamp;
            emit NewPublisherSubmitted(pendingPublisher.publisher = newPublisher);  
        }
    }

Similar changes can be made to these functions: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L175-L192 https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L194-L212

Tools Used

Visual Studio Code, Remix

Recommended Mitigation Steps

See POC for details.

Handle

ye0lde

Vulnerability details

Impact

Eliminating intermediate variables and reducing state variable references can reduce gas usage and improve code clarity.

Proof of Concept

The handleFees function is here: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L148-L151

I suggest this refactoring for #L148-L151:

		emit NewIBRatio(ibRatio = ibRatio * startSupply / totalSupply());

The updateIBRatio function is here: https://github.com/code-423n4/2021-12-defiprotocol/blob/205d3766044171e325df6a8bf2e79b37856eece1/contracts/contracts/Basket.sol#L266-L272

I suggest this refactoring:

    function updateIBRatio(uint256 newRatio) onlyAuction external override returns (uint256) {

        emit NewIBRatio(ibRatio = newRatio);

        return newRatio; 
    }

Tools Used

Visual Studio Code, Remix

Recommended Mitigation Steps

See POC for details.