Submission Details
Severity:
Re-entrancy Attack Risk
Summary
The claimCut function transfers tokens before updating the contract's state, exposing it to re-entrancy attacks.
Vulnerability Details
If a malicious contract calls claimCut, it can re-enter the function before the state is updated, leading to multiple claims of rewards.
Impact
This allows a malicious actor to drain the contract's funds, leading to severe financial loss.
Tools Used
Manual review
Proof of Concept
This vulnerability occurs because of the token transfer:
_transferReward(player, reward); // Transfer before updating state
playersToRewards[player] = 0; // State update after transfer
Recommendations
Implement the Checks-Effects-Interactions pattern by updating the state before transferring tokens.
playersToRewards[player] = 0;
remainingRewards -= reward;
claimants.push(player);
_transferReward(player, reward);
Rewards breakdown
nSLOC
106This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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