Submission Details
Impact:
Likelihood:
Borrow Token Left in Contract After Swap
Author Revealed upon completion
Root + Impact
Description
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Describe the normal behavior in one or more sentences
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Explain the specific issue or problem in one or more sentences
Normal behavior: All borrowed tokens should be fully swapped to collateral token to repay flash loan.
Issue: _executeOpenOperation uses a strict equality check after 1inch swap:
Risk
Likelihood:
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Reason 1 // Describe WHEN this will occur (avoid using "if" statements)
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Reason 2
Impact:
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Impact 1
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Impact 2
Proof of Concept
uint256 afterSwapBorrowTokenbalance = IERC20(flashParams.borrowToken).balanceOf(address(this));
require(afterSwapBorrowTokenbalance == prevBorrowTokenBalance, "Borrow token left in contract");
Recommended Mitigation
- require(afterSwapBorrowTokenbalance == prevBorrowTokenBalance, "Borrow token left in contract");
+ require(afterSwapBorrowTokenbalance <= prevBorrowTokenBalance, "Borrow token left in contract");
Rewards breakdown
nSLOC
356This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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