MorpheusAI
MorpheusAI
Foundry
22,500 USDC
View results
Previous Next
Submission Details
Severity: low
Valid

Insufficient Gas Fee Estimation for Cross-Chain Message Delivery

crypticdefense

Summary

The L1Sender contract enables cross-chain communication by sending a message from Layer 1 to Layer 2 using the LayerZero protocol. However, the contract does not estimate the required gas fees for this operation, potentially resulting in users providing insufficient funds to cover gas fees. This can cause the transaction to fail, leading to a loss of tokens with an unsuccessful message delivery.

Vulnerability Details

The contract allows users to specify an arbitrary amount of tokens to cover the gas fees for the cross-chain message delivery. However, without a prior estimation of the required fees (using LayerZero's estimateFees() function), users are at risk of underfunding the transaction. Enough gas is required to ensure the message delivery on the destination chain. If the provided msg.value is insufficient, the message fails to be delivered, but the tokens may still be deducted from the user's balance, effectively burning the user's tokens.

function sendMintMessage(address user_, uint256 amount_, address refundTo_) external payable onlyDistribution {
RewardTokenConfig storage config = rewardTokenConfig;
​
bytes memory receiverAndSenderAddresses_ = abi.encodePacked(config.receiver, address(this));
bytes memory payload_ = abi.encode(user_, amount_);
​
ILayerZeroEndpoint(config.gateway).send{value: msg.value}(
config.receiverChainId, // communicator LayerZero chainId
receiverAndSenderAddresses_, // send to this address to the communicator
payload_, // bytes payload
payable(refundTo_), // refund address
address(0x0), // future parameter
bytes("") // adapterParams (see "Advanced Features")
);
}

View the layer zero docs for more details.

Impact

Users may experience direct financial loss due to token burn or loss in transactions intended for cross-chain operations. This issue undermines user trust in the contract's reliability for cross-chain functionality and poses a risk of token loss.

Tools Used

Manual review.

Recommendations

Integrate LayerZero's estimateFees() function to estimate the required gas fees for cross-chain message delivery. This can be used to inform users of the minimum msg.value needed or to automatically include the estimated fees in the transaction.

Updates

Lead Judging Commences

inallhonesty Lead Judge over 1 year ago
Submission Judgement Published
Validated
Assigned finding tags:

LayerZero Integration: `sendMintMessage` doesn't verify the `msg.value` sent by the user facilitating failed transactions.

Support

FAQs

Can't find an answer? Chat with us on Discord, Twitter or Linkedin.