Sturdy contest - CertoraInc's results

Lines of code

https://github.com/code-423n4/2022-05-sturdy/blob/78f51a7a74ebe8adfd055bdbaedfddc05632566f/smart-contracts/LidoVault.sol#L140

Vulnerability details

Impact

The protocol suppose to send ETH to the user, but in case of fail, nothing will check it.

Proof of Concept

the code is

 140     (bool sent, bytes memory data) = address(_to).call{value: receivedETHAmount}('');
 141     return receivedETHAmount;
 142      require(sent, Errors.VT_COLLATERAL_WITHDRAW_INVALID);

it means that if the call to _to will fail , and sent==false, won't be check of this because the function will return before.

Recommended Mitigation Steps

I recommend to switch between lines 141 and 142. new code:

 140     (bool sent, bytes memory data) = address(_to).call{value: receivedETHAmount}('');
 141      require(sent, Errors.VT_COLLATERAL_WITHDRAW_INVALID);
 142      return receivedETHAmount;