Submission Details
Severity:
Outdated Solidity version
Summary
The solidity version 0.8.13 doesn't support block.prevrandao
Vulnerability Details In twentyOne::drawcard function
uint256 randomIndex = uint256(
keccak256(
abi.encodePacked(block.timestamp, msg.sender, block.prevrandao) //-->> It will throw an error
)
) % availableCards[player].length;
Impact
The compiler will throw an error
Tools Used
solidity complier
Manual review
Recommendations
Use newer versions of solidity
Eg: ^0.8.20
Updates
Lead Judging Commences
inallhonesty 11 months ago
Submission Judgement Published Assigned finding tags:
`block.prevrandao` usage fails with pragmas below 0.8.18
Rewards breakdown
nSLOC
147This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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