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Submission Details
Severity: medium
Valid

Transaction revert if the baseToken does not support 0 value transfer when charging fee

Rolezn

Summary

When calling the functions, the caller needs to the pay the fee on the baseToken transfer. If the fee amount is 0, the code below would revert if the ERC20 token does not support 0 value transfer as according to https://github.com/d-xo/weird-erc20#revert-on-zero-value-transfers

Impact

Transaction revert if the baseToken does not support 0 value transfer when charging fee

Proof Of Concept

File: Lender.sol
​
267: IERC20(loan.loanToken).transfer(feeReceiver, fees);
​

https://github.com/Cyfrin/2023-07-beedle/tree/main/src/Lender.sol#L267

File: Lender.sol
​
563: IERC20(loan.collateralToken).transfer(feeReceiver, govFee);
​

https://github.com/Cyfrin/2023-07-beedle/tree/main/src/Lender.sol#L563

File: Lender.sol
​
651: IERC20(loan.loanToken).transfer(feeReceiver, fee);

https://github.com/Cyfrin/2023-07-beedle/tree/main/src/Lender.sol#L651

Recommended Mitigation Steps

It is recommended for the protocol to check if the fee amount is 0 before performing transfer, i.e.

if(fees > 0) {
IERC20(loan.loanToken).transfer(feeReceiver, fees);
}

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