Submitted by davidbrai, also found by cccz, Ch_301, Chom, datapunk, elad, GimelSec, pauliax, PwnPatrol, and rbserver
https://github.com/code-423n4/2022-09-nouns-builder/blob/main/src/governance/governor/Governor.sol#L128
https://github.com/code-423n4/2022-09-nouns-builder/blob/main/src/governance/governor/Governor.sol#L363
If the proposer of a proposal has votes in the same amount as the proposalThreshold, they can create a proposal. But in this case, anyone can also cancel this proposal.
When creating a proposal the requirement is Ensure the callers voting weight is greater than or equal to the threshold.
When cancelling a proposal the check is:
if getVotes(proposal.proposer, block.timestamp - 1) > proposal.proposalThreshold then it the cancelling is not allowed. In effect, if the number of votes is lower than or equal to the proposalThreshold it can be cancelled.
In the extreme case where all the DAO members have no more than the proposalThreshold amount of votes, every proposal can be cancelled.
The forge test below demonstrates the issue:
Change the check in cancel to match the requirement in propose;
change line 363 in Governor.sol to:
if (msg.sender != proposal.proposer && getVotes(proposal.proposer, block.timestamp - 1) >= proposal.proposalThreshold)
Alex the Entreprenerd (judge) decreased severity to Medium and commented:
kulkarohan (Nouns Builder) confirmed, but disagreed with severity
