Core Contracts

Summary

ZENO.sol is ERC20, so it is going to have all ERC20.sol functions including decimals() that returns 18 by default.

Vulnerability Details

The issue is that ZENO.sol doesn't override decimals().
https://github.com/OpenZeppelin/openzeppelin-contracts/blob/9586aaf35241daf4b17e4858bf7c86edbb4b7247/contracts/token/ERC20/ERC20.sol#L78

However, this may lead to confuse users asuming ZENO tokens have 18 decimals.
While ZENO tokens doesn't use the decimals in any calculation since it is designed to be purchased one to one with stable coins.

Impact

decimals() returns false value.

Tools Used

Manual Review.

Recommendations

override the decimals() function and return 0.