Submitted by rbserver, also found by 0x1f8b, Bahurum, csanuragjain, and yixxas
https://github.com/code-423n4/2022-08-olympus/blob/main/src/modules/VOTES.sol#L9-L11
https://github.com/code-423n4/2022-08-olympus/blob/main/src/policies/Governance.sol#L180-L201
https://github.com/code-423n4/2022-08-olympus/blob/main/src/policies/Governance.sol#L205-L236
The following comment indicates that the OlympusVotes contract is a stub for gOHM. Checking the gOHM contract at https://etherscan.io/token/0x0ab87046fBb341D058F17CBC4c1133F25a20a52f#code, the transfer and transferFrom functions are available.
https://github.com/code-423n4/2022-08-olympus/blob/main/src/modules/VOTES.sol#L9-L11
Moreover, the documentation states that the vote redemption mechanism exists to deter malicious behavior by ensuring users cannot transfer their voting tokens until after the proposal has been resolved, which also indicates that the voting tokens are meant to be transferrable between users.
When the voting tokens are transferrable, one user can first use her or his votes to call the following endorseProposal function to endorse a proposal and then transfer these votes to another user. The other user can use these votes to endorse the same proposal again afterwards. Because of the double-endorsement, the (totalEndorsementsForProposal[proposalId_] * 100) < VOTES.totalSupply() * ENDORSEMENT_THRESHOLD condition can become true so the proposal can be activated by calling the activateProposal function below. However, the proposal should only be endorsed with these same votes once and should not be able to be activated if it could not satisify (totalEndorsementsForProposal[proposalId_] * 100) < VOTES.totalSupply() * ENDORSEMENT_THRESHOLD with these votes being used once.
https://github.com/code-423n4/2022-08-olympus/blob/main/src/policies/Governance.sol#L180-L201
https://github.com/code-423n4/2022-08-olympus/blob/main/src/policies/Governance.sol#L205-L236
Please append the following test in src\test\policies\Governance.t.sol. This test will pass to demonstrate the described scenario.
VSCode
When calling endorseProposal, the users votes can be locked by transferring these votes to the governance so the user cannot transfer these anymore to another user after the endorsement. An additional function can be added for reclaiming the endorsed votes back to the user and reducing the proposals endorsed votes accordingly before the proposal is activated. After the proposal is activated, the endorsed votes should be counted as the voted votes.
fullyallocated (Olympus) acknowledged and commented:
