InsureDAO contest - Meta0xNull's results

Handle

Meta0xNull

Vulnerability details

Impact

A wrong user input or wallets defaulting to the zero addresses for a missing input can lead to the contract needing to redeploy or wasted gas.

Proof of Concept

https://github.com/code-423n4/2022-01-insure/blob/main/contracts/Factory.sol#L81-L83

Tools Used

Manual Review

Recommended Mitigation Steps

Requires Addresses is not zero.

require(_registry != address(0), "Address Can't Be Zero") require(_ownership != address(0), "Address Can't Be Zero")

Handle

Meta0xNull

Vulnerability details

Impact

Shortening revert strings to fit in 32 bytes will decrease deployment time gas and will decrease runtime gas when the revert condition has been met.

Revert strings that are longer than 32 bytes require at least one additional mstore, along with additional overhead for computing memory offset, etc.

Proof of Concept

https://github.com/code-423n4/2022-01-insure/blob/main/contracts/Ownership.sol#L39 https://github.com/code-423n4/2022-01-insure/blob/main/contracts/Ownership.sol#L47

Tools Used

Manual Review

Recommended Mitigation Steps

Shorten the revert strings to fit in 32 bytes.

Or consider using Custom Errors (solc >=0.8.4).

Handle

Meta0xNull

Vulnerability details

Impact

The local variable used as for loop index need not be initialized to 0 because the default value is 0. Avoiding this anti-pattern can save a few opcodes and therefore a tiny bit of gas.

Proof of Concept

https://github.com/code-423n4/2022-01-insure/blob/main/contracts/Factory.sol#L176 https://github.com/code-423n4/2022-01-insure/blob/main/contracts/Factory.sol#L186

Tools Used

Manual Review

Recommended Mitigation Steps

for (uint256 i = 0; After for (uint256 i;