First Flight #5: Santa's List

Summary

The collectPresent function in SantasList.sol is susceptible to frontrunning attacks, allowing miners to exploit time-dependent conditions for potential financial gain and other advantages.

Vulnerability Details

The vulnerability arises from the use of block.timestamp to check if it's Christmas before allowing users to collect presents. Miners can manipulate the timestamp to make it appear as if Christmas has arrived, enabling them to front-run transactions and collect rewards prematurely.

Impact

• Miners can exploit the vulnerability to front-run transactions and trigger reward mechanisms before the intended time.

• Users may experience unfair treatment, and the integrity of time-dependent conditions in the smart contract is compromised.

Tools used

• Manual review

Recommendations

• Refrain from relying solely on block.timestamp for time-sensitive conditions. Consider using block numbers or a combination of block numbers and timestamps.

• Consider using commit-reveal schemes, especially in scenarios where confidentiality is crucial. This adds an additional layer of security by introducing a delay between commitment and revelation

• Incorporate randomness into the smart contract logic to make it more challenging for miners to predict outcomes and manipulate transactions.

• Clearly communicate the potential risks associated with frontrunning and timestamp manipulation to users. Provide guidelines for secure interaction with the smart contract.

Implementing these recommendations will enhance the resilience of the smart contract against frontrunning attacks and improve overall security.