First Flight #5: Santa's List

Summary

The smart contract relies on precise timestamp conditions for time-sensitive actions, particularly in the collectPresent function. However, the usage of timestamps in short-term intervals may lead to unpredictable behavior, exacerbated by Arbitrum's handling of block.timestamp. Timestamp information on rollups, as mentioned in Arbitrum's documentation, can be less reliable, introducing potential vulnerabilities.

Vulnerability Details

The primary vulnerability arises from the reliance on block.timestamp for time-sensitive conditions, especially in scenarios where precise timing is crucial. This approach may be susceptible to front-running attacks and can be affected by the variable nature of timestamps on blockchain networks, with particular emphasis on Arbitrum's characteristics. Users are advised to consider the unreliability of timestamps in shorter terms and the potential deviation on rollups.

Impact

The impact of this vulnerability is critical, as it could lead to unintended consequences in the execution of time-sensitive functions. Users may exploit timing variations to gain advantages or disrupt the intended behavior of the smart contract, with additional considerations for Arbitrum's timestamp handling.

Tools Used

• Manual Review

Recommendations

1. Avoid Precise Timestamp Conditions: Consider alternative approaches that are less reliant on precise timestamp conditions. Using block numbers or relative time intervals can provide more robust and predictable outcomes, especially considering Arbitrum's timestamp peculiarities.

2. Check Rollup Documentation: Before deploying on a rollup, review the rollup's documentation on timestamp handling and assess the safety of time-dependent functionality. If needed, increase the deadline threshold to account for potential deviations.

The implementation should be adjusted to enhance resilience against timing-related vulnerabilities, ensuring the secure and reliable execution of time-sensitive functions on Arbitrum.