First Flight #4: Boss Bridge

Summary

The deployToken function in TokenFactory.sol lacks validation for duplicated token symbols.

Vulnerability Details

In the deployToken function, there is no validation to check whether a symbol has already been registered. If a user registers token A with symbol S, and another user deploys token B with the same symbol S, the token mapping from symbol S to token address will be overridden. Subsequently, if the original user triggers getTokenAddressFromSymbol within the same contract, the return value may differ from their expectations.

Impact

Users may receive unexpected token addresses, potentially causing issues such as minting a different token than intended (e.g., minting token B instead of token A).

Tools Used

Manual Review

Recommendations

To mitigate this issue, it is advised to validate the return value by checking whether the symbol has been registered before deploying a new token. Consider adding a validation statement at the beginning of the token deployment, such as require(s_tokenToAddress[symbol] != 0, "Symbol already registered"). This validation step will prevent the override of token symbols and ensure users receive the expected return values.