Beanstalk: The Finale
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Submission Details
Severity: low
Invalid

Beans migration is not possible due to missing gas fee

holydevoti0n

Summary

The migrateL2Beans function in the BeanL2MigrationFacet contract fails to migrate Beans from Ethereum to L2 because it lacks the ability to receive Ether through msg.value, which is necessary to cover the gas fee for the sendMessage function.

Vulnerability Details

The migrateL2Beans function does not include the payable modifier, preventing it from receiving Ether needed for the gas fee in the sendMessage function call.

contract BeanL2MigrationFacet is Invariable, ReentrancyGuard {
address constant BRIDGE = address(0x866E82a600A1414e583f7F13623F1aC5d58b0Afa);
​
​
/**
* @notice migrates `amount` of Beans to L2,
* issued to `reciever`.
*/
function migrateL2Beans(
address reciever,
address L2Beanstalk,
uint256 amount,
uint32 gasLimit
@> ) external nonReentrant {
C.bean().burnFrom(msg.sender, amount);
​
​
// send data to
IL2Bridge(BRIDGE).sendMessage(
L2Beanstalk,
abi.encodeCall(IBeanL1RecieverFacet(L2Beanstalk).recieveL1Beans, (reciever, amount)),
gasLimit
);
}

The function cannot receive Ether because it lacks the payable modifier, resulting in the inability to provide the necessary gas fee for the sendMessage function call.

Impact

DoS - Due to the inability to cover the gas fee, the Beans migration process from Ethereum to L2 is not possible.

Tools Used

Manual Review

https://docs.optimism.io/stack/protocol/rollup/deposit-flow

Recommendations

Add a payablemodifier for the function and also a check to ensure the gas fees are being sent.

function migrateL2Beans(
address reciever,
address L2Beanstalk,
uint256 amount,
uint32 gasLimit
- ) external nonReentrant {
+ ) external payable nonReentrant {
+ require(msg.value > 0, "Gas payment is required");
C.bean().burnFrom(msg.sender, amount);
​
​
// send data to
IL2Bridge(BRIDGE).sendMessage(
L2Beanstalk,
abi.encodeCall(IBeanL1RecieverFacet(L2Beanstalk).recieveL1Beans, (reciever, amount)),
gasLimit
);
}
Updates

Lead Judging Commences

inallhonesty Lead Judge about 1 year ago
Submission Judgement Published
Invalidated
Reason: Non-acceptable severity
Assigned finding tags:

Beans migration is not possible due to missing gas fee

Appeal created

holydevoti0n Submitter
12 months ago
golanger85 Auditor
12 months ago
inallhonesty Lead Judge
12 months ago
inallhonesty Lead Judge 12 months ago
Submission Judgement Published
Invalidated
Reason: Known issue
Assigned finding tags:

Beans migration is not possible due to missing gas fee

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