First Flight #2: Puppy Raffle

Vulnerability Details

Pragma versions are designed in a way that 0.x.0 introduces breaking changes and 0.0.x introduces bug fixes in the previous versions.

Now using ^ with the pragma versions opens the code compilation till the next < 0.x.0 version, There will be no breaking changes until version 0.x.0, you can be sure that your code compiles the way you intended but due to the exact version of the compiler is not fixed, newly introduced bugfix can still affect the code.

It is recommended by Solidity Docs to use fixed version for your projects.

Which version should we choose?

Well, Solidity docs always suggest using the latest version of Solidity for the deployment of smart contracts.

Tools Used

Manual Review

Recommendations

Consider locking the pragma version in the smart contracts. It is not recommended to use a floating pragma in production.