MyCut
AI First Flight #8
Beginner FriendlyFoundry
EXP
View results
Previous Next
Submission Details
Severity: low
Valid

Lack of events on state-changing functions reduces transparency and monitorability

hopeh

Description


The protocol's state-changing functions do not emit any events, making it hard to monitor contests, claims, funding, and closures off-chain.


// ContestManager: createContest / fundContest / closeContest -> no events
// Pot: claimCut / closePot -> no events
```
​
None of these functions emit an event for the important state transitions (a contest being created, a pot being funded, a player claiming, a pot being closed and distributed).
​
## Risk
​
**Likelihood: Low**
​
- Affects observability rather than on-chain safety; it manifests whenever an off-chain system (indexer, dashboard, alerting) needs to track protocol activity.
​
**Impact: Low**
​
- Lack of events reduces transparency and makes it difficult to monitor the protocol, reconcile balances, or detect anomalies. It complicates integrations and incident response but does not directly cause loss of funds.
​
## Proof of Concept
​
```solidity
// A claim changes state but emits nothing:
function claimCut() public {
...
playersToRewards[player] = 0;
remainingRewards -= reward;
_transferReward(player, reward);
// @> no emit ClaimCut(player, reward);
}
```
​
## Recommended Mitigation
​
Emit events for every meaningful state change:
​
```solidity
event ContestCreated(address pot, uint256 totalRewards);
event ContestFunded(address pot, uint256 amount);
event CutClaimed(address player, uint256 amount);
event PotClosed(address pot, uint256 managerCut, uint256 claimantCut);
```
}
Updates

Lead Judging Commences

ai-first-flight-judge Lead Judge about 4 hours ago
Submission Judgement Published
Validated
Assigned finding tags:

[L-02] Lack of events which reduces transparency and difficulty in monitoring

**Description** The `ContestManager` contract lacks event emissions for critical actions such as creating, funding, and closing contests. Events are crucial in Solidity contracts for logging important actions, as they provide an immutable record on the blockchain that can be indexed and queried by off-chain applications. Without these events, tracking the state and history of the contract becomes difficult, which can hinder monitoring, debugging, and auditing efforts. **Impact** - **Visibility**: Without events, external parties (such as users or monitoring systems) cannot easily track when contests are created, funded, or closed. This lack of visibility can lead to difficulties in verifying the correct operation of the contract. - **Debugging**: Developers and auditors will find it more challenging to diagnose issues or verify contract behavior without event logs. In the event of a bug or issue, the absence of events makes it harder to trace the sequence of actions leading up to the problem. - **Transparency**: Participants in the contests might not have a clear understanding of the state of the contract, which could lead to mistrust or uncertainty. **Proof of Concepts** The following functions in the `ContestManager` contract are identified as lacking event emissions: - `createContest` - `fundContest` - `closeContest` For example, in the `createContest` function: ```solidity function createContest(address[] memory players, uint256[] memory rewards, IERC20 token, uint256 totalRewards) public onlyOwner returns (address) { Pot pot = new Pot(players, rewards, token, totalRewards); contests.push(address(pot)); contestToTotalRewards[address(pot)] = totalRewards; // No event emitted to signal that a new contest has been created. return address(pot); } ``` **Recommended Mitigation:** Add event declarations and emit statements in the contract to log significant actions. ```solidity event ContestCreated(address indexed contestAddress, uint256 totalRewards); event ContestFunded(address indexed contestAddress, uint256 amount); event ContestClosed(address indexed contestAddress); ```

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.

Give us feedback!