Remove salt from createPair()

[code423n4]

Handle

sirhashalot

Vulnerability details

Impact

The createPair() function in TimeswapFactory.sol passes a salt value to when creating a new TimeswapPair. This salt is never used. Most likely the salt is an artifact from Uniswap V2 Core code. However, Uniswap v2 Core only uses a salt for the CREATE2 assembly call, which is not used in the Timeswap project.
https://docs.uniswap.org/protocol/V2/guides/smart-contract-integration/getting-pair-addresses

Proof of Concept

The unnecessary salt is found at:
https://github.com/code-423n4/2022-01-timeswap/blob/bf50d2a8bb93a5571f35f96bd74af54d9c92a210/Timeswap/Timeswap-V1-Core/contracts/TimeswapFactory.sol#L52

Recommended Mitigation Steps

Don't pass a salt when creating a pair. The revised line of code should look like:
pair = new TimeswapPair(asset, collateral, fee, protocolFee);

[Mathepreneur]

It is currently not in used, but a different convenience contract or proxy contract might find this feature useful.