Project

Summary

The NativeMetaTransaction.sol contract includes a function called executeMetaTransaction for executing meta-transactions. This function includes a callback to the contract itself, passing some data and value. However, the contract lacks both a receive and fallback function, which are necessary for handling certain types of calls. This oversight introduces potential risks, including denial-of-service (DoS) attacks.

Vulnerability Details

In the NativeMetaTransaction.sol contract:

Impact

The absence of receive and fallback functions in the contract exposes it to several risks:

• Loss of Funds: Without a receive or fallback function, the contract cannot accept Ether directly. Any attempt to send Ether to this contract will result in a failed transaction, causing a loss of funds. This can have significant consequences, especially in scenarios where contract interactions are expected to include Ether transfers.

• Limited Functionality: The inability to handle incoming Ether restricts the contract's interoperability with other contracts or users that may need to send Ether to it. This limitation hinders the contract’s utility and could break critical workflows.

• Security Risks: While the lack of a fallback function can mitigate certain attack vectors (such as unexpected Ether transfers), it also limits the contract’s ability to defend against others. For instance, without a custom fallback function, the contract cannot reject or manage unwanted Ether transfers, leaving it susceptible to certain DoS scenarios.

Tools Used

Manual Code Review

Recommendations

To mitigate the risks associated with the missing fallback functionality, it is strongly recommended to implement both a receive function and a fallback function in the contract. These functions are essential for ensuring the contract can properly handle incoming Ether and maintain expected functionality in various scenarios.