GovNFT: maxBridge has no effect

[code423n4]

Lines of code

https://github.com/code-423n4/2022-12-tigris/blob/496e1974ee3838be8759e7b4096dbee1b8795593/contracts/GovNFT.sol#L19-L20

Vulnerability details

Impact

In GovNFT, setMaxBridge function is provided to set maxBridge, but this variable is not used, literally it should be used to limit the number of GovNFTs crossing chain, but it doesn't work in GovNFT.

    uint256 public maxBridge = 20;
...
    function setMaxBridge(uint256 _max) external onlyOwner {
        maxBridge = _max;
    }

Proof of Concept

https://github.com/code-423n4/2022-12-tigris/blob/496e1974ee3838be8759e7b4096dbee1b8795593/contracts/GovNFT.sol#L19-L20
https://github.com/code-423n4/2022-12-tigris/blob/496e1974ee3838be8759e7b4096dbee1b8795593/contracts/GovNFT.sol#L311-L313

Tools Used

None

Recommended Mitigation Steps

Consider applying the maxBridge variable

[GalloDaSballo]

R

[c4-judge]

GalloDaSballo changed the severity to QA (Quality Assurance)

[GainsGoblin]

I disagree with the severity downgrade.

[c4-sponsor]

GainsGoblin requested judge review

[GalloDaSballo]

@GainsGoblin Thank you for flagging.

I have checked the LayerZero Library and it seems like it will not revert when relaying a tx that is too expensive.

For this reason I agree with you and will raise Severity to Medium.

The Warden has shown how, an unused variable, which was meant to cap the amount of tokens bridged per call, could cause a DOS.

These types of DOS could only be fixed via Governance Operations, and could create further issues, for this reason I agree with Medium Seveirty

[Simon-Busch]

Reverted back to M and set as Primary issue as requested by @GalloDaSballo

[c4-judge]

GalloDaSballo marked the issue as selected for report

[GainsGoblin]

Mitigation: code-423n4/2022-12-tigris#2 (comment)

[c4-sponsor]

GainsGoblin marked the issue as sponsor confirmed