FEI and TRIBE Redemption contest - rotcivegaf's results

QA report

Non-critical

[N-01] The contracts use unlocked pragma

In contracts/peg/SimpleFeiDaiPSM.sol and contracts/shutdown/redeem/TribeRedeemer.sol lock the pragma to an specific version

[N-02] Burn receive tokens

The contracts/shutdown/redeem/TribeRedeemer.sol could burn the tokens received by redeem function

    function redeem(address to, uint256 amountIn) external nonReentrant {
+       IERC20 _redeemedToken = IERC20(redeemedToken);
-       IERC20(redeemedToken).safeTransferFrom(msg.sender, address(this), amountIn);
+       _redeemedToken.safeTransferFrom(msg.sender, address(this), amountIn);
+       _redeemedToken.burn(amountIn);

        (address[] memory tokens, uint256[] memory amountsOut) = previewRedeem(amountIn);

        uint256 base = redeemBase;
        redeemBase = base - amountIn; // decrement the base for future redemptions
        for (uint256 i = 0; i < tokens.length; i++) {
            IERC20(tokens[i]).safeTransfer(to, amountsOut[i]);
        }

        emit Redeemed(msg.sender, to, amountIn, base);
    }

[N-03] Typo

In contracts/shutdown/fuse/RariMerkleRedeemer.sol#L164: From: /// Should set the user's claim amount int he claims mapping for the provided cToken To: // Should set the user's claim amount in the claims mapping for the provided cToken

Low Risk

[L-01] Events are not indexed

The emitted events are not indexed, making off-chain scripts such as front-ends of dApps difficult to filter the events efficiently.

Recommended Mitigation Steps: Add the indexed keyword in filter parameters of the events

In contracts/peg/SimpleFeiDaiPSM.sol: From:

L27: event Redeem(address to, uint256 amountFeiIn, uint256 amountAssetOut);
L29: event Mint(address to, uint256 amountIn, uint256 amountFeiOut);

To:

L27: event Redeem(address indexed to, uint256 amountFeiIn, uint256 amountAssetOut);
L29: event Mint(address indexed to, uint256 amountIn, uint256 amountFeiOut);

[L-02] In the function previewRedeem in contracts/shutdown/redeem/TribeRedeemer.sol the amountIn should be lower or equal than base by definition

  function previewRedeem(uint256 amountIn)
      public
      view
      returns (address[] memory tokens, uint256[] memory amountsOut)
  {
      tokens = tokensReceivedOnRedeem();
      amountsOut = new uint256[](tokens.length);

      uint256 base = redeemBase;
+     require(base >= amountsIn, "High amountsIn");
      for (uint256 i = 0; i < tokensReceived.length; i++) {
          uint256 balance = IERC20(tokensReceived[i]).balanceOf(address(this));
          require(balance != 0, "ZERO_BALANCE");
          // @dev, this assumes all of `tokensReceived` and `redeemedToken`
          // have the same number of decimals
          uint256 redeemedAmount = (amountIn * balance) / base;
          amountsOut[i] = redeemedAmount;
      }
  }

[L-03] Validate constructor parameters(TribeRedeemer.sol)

In the constructor of contracts/shutdown/redeem/TribeRedeemer.sol:

• The _redeemedToken parameter should not be the address(0)
• All tokens inside _tokensReceived array should not be address(0)
• The _redeemBase parameter should not be 0

    constructor(
        address _redeemedToken,
        address[] memory _tokensReceived,
        uint256 _redeemBase
    ) {
+       require(_redeemedToken != address(0), "_redeemedToken should not be address(0)");
        redeemedToken = _redeemedToken;
+       uint256 _tokensReceivedLength;
+       for (uint256 i; i < _tokensReceivedLength;) {
+           require(_tokensReceived[i] != address(0), "All tokensReceived should not be address(0)");
+           unchecked{ ++i; }
+       }
        tokensReceived = _tokensReceived;
+       require(_redeemBase != 0, "_redeemBase should not be 0");
        redeemBase = _redeemBase;
    }

[L-04] Validate constructor parameters(RariMerkleRedeemer.sol)

In the constructor of contracts/shutdown/fuse/RariMerkleRedeemer.sol the cTokens should not contains any address(0)

    constructor(
        address token,
        address[] memory cTokens,
        uint256[] memory rates,
        bytes32[] memory roots
    ) {
+       uint256 cTokensLength;
+       for (uint256 i; i < cTokensLength;) {
+           require(cTokens[i] != address(0), "All cTokens should not be address(0)");
+           unchecked{ ++i; }
+       }
        _configureExchangeRates(cTokens, rates);
        _configureMerkleRoots(cTokens, roots);
        _configureBaseToken(token);
    }

[L-05] Poor signature message

The MESSAGE_HASH used in _sign in RariMerkleRedeemer.sol#L155 defined in MultiMerkleRedeemer.sol#L56 use a poor message "Sample message, please update." This message don't represent anything, also says update it

[L-06] The rates on RariMerkleRedeemer.sol could expire

The rates setter in the constructor of contracts/shutdown/fuse/RariMerkleRedeemer.sol can expire add an expiry date and update the rate in a window time

[L-07] Miss hasNotSigned

In the signAndClaim function miss hasNotSigned modifier