First Flight #17: Dussehra

Summary

Dangerous usage of block.timestamp. block.timestamp can be manipulated by miners.

Vulnerability Details

Following are the areas that are using block timestamp for comparisons which can be manipulated by the miners
In ChoosingRam::increaseValuesOfParticipants()

function increaseValuesOfParticipants(uint256 tokenIdOfChallenger, uint256 tokenIdOfAnyPerticipent)
    public
    RamIsNotSelected
{
    ...

    @>   if (block.timestamp > 1728691200) {
        revert ChoosingRam__TimeToBeLikeRamFinish();
    }
    ...
}

In ChoosingRam ::selectRamIfNotSelected()

function selectRamIfNotSelected() public RamIsNotSelected OnlyOrganiser {
 @>    if (block.timestamp < 1728691200) {
        revert ChoosingRam__TimeToBeLikeRamIsNotFinish();
    }
 @>    if (block.timestamp > 1728777600) {
        revert ChoosingRam__EventIsFinished();
    }
    
    uint256 random = uint256(keccak256(abi.encodePacked(block.timestamp, block.prevrandao))) % ramNFT.tokenCounter();
    selectedRam = ramNFT.getCharacteristics(random).ram;
    isRamSelected = true;
}

In Dussehra::killRavana()

function killRavana() public RamIsSelected {
    @>  if (block.timestamp < 1728691069) {
        revert Dussehra__MahuratIsNotStart();
    }
    @>  if (block.timestamp > 1728777669) {
        revert Dussehra__MahuratIsFinished();
    }
    IsRavanKilled = true;
    uint256 totalAmountByThePeople = WantToBeLikeRam.length * entranceFee;
    totalAmountGivenToRam = (totalAmountByThePeople * 50) / 100;
    (bool success, ) = organiser.call{value: totalAmountGivenToRam}("");
    require(success, "Failed to send money to organiser");
}

Impact

Miners can manipulate the timestamp for extending the time period of event for their own benefits.

Tools Used

Manual Review

Recommendations

Avoid relying on block.timestamp.