removeBlackList() may emit error message

Summary

removeBlackList() may emit an error message

Vulnerability Detail

   function removeBlackList(address clearedUser) public onlyGuardian {
        isBlackListed[clearedUser] = false;
        emit RemovedBlackList(clearedUser);  
    }

This function is to remove blacklist. The issue is it has no existing check, whatever param is, it will emit a message, if clearedUser does not exist, remove msg will also be emitted.

Impact

Error emit message will be Emit. POC: paste below code in ERC20Token.t.sol

function testRemoveBlackListErrorMsg() public {
        vm.startPrank(Guardian);
        token.removeBlackList(address(0) );
        token.removeBlackList(address(0) );
        token.removeBlackList(address(0) );
        vm.stopPrank();
    }

command: forge test --match-test testRemoveBlackListErrorMsg -vvvv

Code Snippet

https://github.com/sherlock-audit/2023-04-unitasprotocol/blob/main/Unitas-Protocol/src/ERC20Token.sol#L272-275

Tool used

Manual Review

Recommendation

add existing check

sherlock-audit / 2023-04-unitasprotocol-judging

twcctop - removeBlackList() may emit error message #124