007.md

Docile Corduroy Camel

Medium

Users can grief market graduation and make markets ungraduatable

Summary

When checking for a market to be graduated, we use ReputationMarket.sol::_checkMarketExists(). This way if the market creator has sold his votes, or is the last one to sell his votes, then the market becomes ungraduatable.

function _checkMarketExists(uint256 profileId) private view {
    if (markets[profileId].votes[TRUST] == 0 && markets[profileId].votes[DISTRUST] == 0)
      revert MarketDoesNotExist(profileId);
}

As there is no check for votes becoming 0 when selling votes this is possible and may happen even unknowingly by users that are not aware of this limitation. Part of the ReputationMarket.sol::sellVotes() function:

    (uint256 proceedsBeforeFees, uint256 protocolFee, uint256 proceedsAfterFees) = _calculateSell(
      markets[profileId],
      profileId,
      isPositive,
      votesToSell
    );

    uint256 pricePerVote = votesToSell > 0 ? proceedsBeforeFees / votesToSell : 0;
    if (pricePerVote < minimumVotePrice) {
      revert SellSlippageLimitExceeded(minimumVotePrice, pricePerVote);
    }

    markets[profileId].votes[isPositive ? TRUST : DISTRUST] -= votesToSell;
    votesOwned[msg.sender][profileId].votes[isPositive ? TRUST : DISTRUST] -= votesToSell;

And in the ReputationMarket.sol::_calculateSell() function we have no check if votes after sell == 0. Part of the ReputationMarket.sol::_calculateSell() function:

uint256 votesAvailable = votesOwned[msg.sender][profileId].votes[isPositive ? TRUST : DISTRUST];
    if (votesToSell > votesAvailable) revert InsufficientVotesOwned(profileId, msg.sender);

    if (market.votes[isPositive ? TRUST : DISTRUST] < votesToSell)
      revert InsufficientVotesToSell(profileId);

Root Cause

It is possible for a contract to be left out with 0 votes of TRUST and DISTRUST after selling of votes. This will lead to markets that cannot be graduated.

Internal Pre-conditions

No response

External Pre-conditions

No response

Attack Path

No response

Impact

(Griefing of markets/selling by mistake) will lead to many markets that can' be graduated.

PoC

No response

Mitigation

No response