code423n4 commented 1 year ago

Lines of code

https://github.com/code-423n4/2023-04-frankencoin/blob/1022cb106919fba963a89205d3b90bf62543f68f/contracts/Frankencoin.sol#L152

Vulnerability details

Impact

The human factor, the network factor, the factor of force majeure, the factor of validators in the approach when the submission of a minter must survive a certain period of time to be approved leads to the fact that it will not work to impose a veto and the unwanted minter will be approved. Which will lead to fatal consequences

Proof of Concept

The approach to become a minter is as follows:

Apply for a minter
Wait for a certain period
No one vetoes your submission
Automatic confirmation of minter status

This approach leads to the fact that if you are not vetoed, you become a minter.

But there are quite a few reasons why you were not vetoed:

Communication problems with stakeholders who can set veto
Interested blockchain validators do not miss the application for the veto of the chosen minter
Problems with stakeholders' technical equipment
Simple negligence from stakeholders
Or bugs in programs that do not monitor the appearance of an application for a minter
Reorganization of the blocks and not including the veto tx in the block
Simple ignoring
Many other factors

A single factor or several in a pile can lead to the fact that an unwanted minter will survive this period and become approved

Which will lead to fatal consequences, the bigger the project, the greater the chance of this

therefore, you should not rely on mechanism: if you are ignored, you will become a minter. you need to conduct minimal confirmation and additional waiting to become a minter or another flow

Tools Used

Manual review
Hardhat

Recommended Mitigation Steps

Change the approach from waiting for the approved status to minimal approval with waiting. To make it impossible to become a minter without confirmation
Replace the mechanism of simple waiting without veto, for approval with waiting