First Flight #2: Puppy Raffle

Summary

Bug 1: There are various risks associated with using an outdated version of Solidity.
Bug 2: There are various risks associated with using an outdated version of Openzeppelin.

Vulnerability Reference Links: OpenZeppelin version、[Outdated Solidity version in use

Impact

1. e.g. overflow vulnerabilities are prevalent in versions of Solidity up to 0.8, etc. (see https://soliditylang.org/blog/category/releases/ for bug fixes by version).

2. outdated version of OZ is used (known vulnerabilities exist in this version, see https:// security.snyk.io/package/npm/@openzeppelin%2Fcontracts )

Tools Used

Manual Review

Recommendations

It is recommended to use Solidity^0.8 and the latest version, and the latest version of Openzeppelin.