Submission Details
Severity:
STORAGE_LAYOUT_COLLISION_FOR_UPGRADED_CONTRACT
Summary
Inconsistent storage layout on the old and new ThunderLoan that will be overwritten
Vulnerability Details
Contract ThunderLoan has the following storage layout:
mapping(IERC20 => AssetToken) public s_tokenToAssetToken;
uint256 private s_feePrecision;
uint256 private s_flashLoanFee;
mapping(IERC20 token => bool currentlyFlashLoaning) private s_currentlyFlashLoaning;
While ThunderLoanUpgraded has the following:
mapping(IERC20 => AssetToken) public s_tokenToAssetToken;
uint256 private s_flashLoanFee; // 0.3% ETH fee
// uint256 public constant FEE_PRECISION = 1e18; Not in storage now
mapping(IERC20 token => bool currentlyFlashLoaning) private s_currentlyFlashLoaning;
Impact
Incorrect value for state variables s_flashLoanFee, s_currentlyFlashLoaning after upgrade
Tools Used
Recommendations
Do not change the existed storage layout for the upgraded contract
Updates
Lead Judging Commences
0xnevi almost 2 years ago
Submission Judgement Published Assigned finding tags:
storage collision on upgrade
Rewards breakdown
nSLOC
387This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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