Core Contracts

Summary

The ZENO contract does not override the decimals() function from OpenZeppelin's ERC-20 implementation, which defaults to 18 decimals. However, according to the sponsor, ZENO is intended to have 6 decimals, as it is paired with USDC.

Vulnerability Details

The ZENO contract inherits OpenZeppelin's ERC-20, which implements decimals function like this:

But in Zeno contract there is no decimals function overriding. Therefore without overriding decimals(), the contract may not function as expected, leading to potential inconsistencies in token calculations.

Impact

Discrepancy in decimal precision may cause incorrect token transfers, balances, or integrations with external systems expecting 6 decimals.

Tools Used

Manual Review

Recommendations

Override the decimals() function to return 6 to align with USDC. Add this code to Zeno contract.