Unnecessary Use of _msgSender()

[code423n4]

Handle

defsec

Vulnerability details

Impact

The use of _msgSender() when there is no implementation of a meta transaction mechanism that uses it, such as EIP-2771, very slightly increases gas consumption.

Proof of Concept

1. Navigate to the following contracts.

"https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/FeeSplitter.sol#L135"
"https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/NestedFactory.sol#L111"
"https://github.com/code-423n4/2021-11-nested/blob/5d113967cdf7c9ee29802e1ecb176c656386fe9b/contracts/NestedReserve.sol#L32"

Tools Used

Code review

Recommended Mitigation Steps

Replace _msgSender() with msg.sender if there is no mechanism to support meta-transactions like EIP-2771 implemented.

[maximebrugel]

Only agree for :

modifier onlyFactory() {
   require(_msgSender() == factory, "NestedReserve: UNAUTHORIZED");
    _;
}

For the others, without support for meta transactions in the recipient contract, an externally owned account can not use meta transactions to interact with releaseETH and create