MixinOperatorResolver.sol#isResolverCached() become malfunctioning when an operator is removed

[code423n4]

Handle

WatchPug

Vulnerability details

When an operator is removed and rebuildCache() is called, isResolverCached() should return true. It returns false in the current implemenbtation.

https://github.com/code-423n4/2021-11-nested/blob/f646002b692ca5fa3631acfff87dda897541cf41/contracts/MixinOperatorResolver.sol#L45-L56

/// @notice Check the state of addressCache
function isResolverCached() external view returns (bool) {
    bytes32[] memory requiredAddresses = resolverAddressesRequired();
    for (uint256 i = 0; i < requiredAddresses.length; i++) {
        bytes32 name = requiredAddresses[i];
        // false if our cache is invalid or if the resolver doesn't have the required address
        if (resolver.getAddress(name) != addressCache[name] || addressCache[name] == address(0)) {
            return false;
        }
    }
    return true;
}

Beacuse when an operator is removed, requiredAddresses will includes empty items, so that addressCache[name] will be address(0), and return false.

Recommendation

Change to:

/// @notice Check the state of addressCache
function isResolverCached() external view returns (bool) {
    bytes32[] memory requiredAddresses = resolverAddressesRequired();
    for (uint256 i = 0; i < requiredAddresses.length; i++) {
        bytes32 name = requiredAddresses[i];
        // false if our cache is invalid or if the resolver doesn't have the required address
        if (resolver.getAddress(name) != addressCache[name]) {
            return false;
        }
    }
    return true;
}

[maximebrugel]

Same issue as #139 but not pointing removeOperator.
The issue will be fixed in #58, so i see it as a replicate.

[alcueca]

Duplicate of #139, then