yAudit RAMSES Review

Review Resources:

RAMSES documentation

Auditors:

Jackson
prady
engn33r

Review Summary
Scope
Code Evaluation Matrix
Findings Explanation
Critical Findings
High Findings
1. 1. High - Minting with different position indices yields a higher total boostAmount than minting with the same index
Medium Findings
Low Findings
Gas Saving Findings
Informational Findings
Final remarks

Review Summary

RAMSES

RAMSES is a ve(3,3) DEX that builds on Solidly, but with many improvements. RAMSES v1 has managed millions in TVL, and the new v2 contract files improve upon the existing protocol. The primary upgrade is the staking feature, with much of the other code derived from Uniswap v3.

The contracts of the RAMSES Repo were reviewed over 35 days. The code review was performed by 3 auditors between June 26 and July 30, 2023. The repository was under active development during the review, but the review was limited to the latest commit at the start of the review. This was commit a850f39fd9b0b4c62af5bf4f4d2089284e75cf8e for the RAMSES Exchange repository, and the review scope was focused on the v2, v2-periphery, v2-staking, and v2-universal-router directories.

Scope

The scope of the review consisted of the contracts in the following directories:

contracts/v2/*
contracts/v2-periphery/*
contracts/v2-staking/*
contracts/v2-universal-router/*

After the findings were presented to the RAMSES team, fixes were made and included in several PRs.

This review is a code review to identify potential vulnerabilities in the code. The reviewers did not investigate security practices or operational security and assumed that privileged accounts could be trusted. The reviewers did not evaluate the security of the code relative to a standard or specification. The review may not have identified all potential attack vectors or areas of vulnerability.

yAudit and the auditors make no warranties regarding the security of the code and do not warrant that the code is free from defects. yAudit and the auditors do not represent nor imply to third parties that the code has been audited nor that the code is free from defects. By deploying or using the code, RAMSES and users of the contracts agree to use the code at their own risk.

Code Evaluation Matrix

Category	Mark	Description
Access Control	Good	Every function that should be protected has proper access control modifiers.
Mathematics	Medium	In most cases the Uniswap libraries are used for mathematical operations. However, in some cases raw mathematical operations are used in lieu of the Uniswap libraries or the dependency LowGasSafeMath libraries.
Complexity	High	Most of the code is forked from Uniswap, however, the new position update logic is new, critical, and highly complex.
Libraries	Good	Most of the new code uses Uniswap and OpenZeppelin libraries where appropriate.
Decentralization	Medium	The protocol developers have roughly the same control as the Uniswap protocol developers. However, RAMSES contracts are upgradeable, whereas Uniswap’s are not.
Code stability	Low	Changes were made to the repository while the audit was on-going.
Documentation	Medium	There is documentation explaining the goals of the protocol however, some of the documentation is outdated and no longer reflects the behavior of the current implementation.
Monitoring	Medium	The core interfaces that users will interact with were forked from Uniswap, which emit events where expected. However, there are places in the new code that do not emit events as expected.
Testing and verification	Low	Very little additional testing was added to the new code paths aside from happy case path tests.

Findings Explanation

Findings are broken down into sections by their respective impact:

Critical, High, Medium, Low impact
- These are findings that range from attacks that may cause loss of funds, impact control/ownership of the contracts, or cause any unintended consequences/actions that are outside the scope of the requirements.
Gas savings
- Findings that can improve the gas efficiency of the contracts.
Informational
- Findings including recommendations and best practices.

Critical Findings

None.

High Findings

1. High - Minting with different position indices yields a higher total `boostAmount` than minting with the same index

Technical Details

When minting or burning the liquidityDelta is added to an existing position’s liquidity to determine the newLiquidity which is used throughout _updatePosition() for various calculations, to include the veRamRatio and newBoostedLiquidity. Eventually a boostedLiquidityCap is calculated using the veRamRatio and hypotheticalLiquidity. This boostedLiquidityCap is intended to limit the amount of newBoostedLiquidity that can be added by a position. However, this can be bypassed by using many small positions rather than the same position. This can be done relatively simply by an attacker by using a different index for their positions, and since a veRamTokenId balance can be re-used by multiple positions, there is no detriment to using multiple positions to mint liquidity.

See this POC illustrating the point in code:

contract AttachTest is Test {

    RamsesV2Pool _pool;
    RamsesV2Factory _factory;
    MockVoter _voter;
    MockNFPManager _nfpManager;
    MockVotingEscrow _veRam;
    MockERC20 _token0;
    MockERC20 _token1;

    function setUp() public {
        _pool = new RamsesV2Pool();
        _factory = new RamsesV2Factory();
        _voter = new MockVoter();
        _nfpManager = new MockNFPManager();
        _veRam = new MockVotingEscrow();
        _token0 = new MockERC20("0", "token_0", 18);
        _token1 = new MockERC20("1", "token_1", 18);

        deal(address(_token0), address(this), type(uint256).max);
        deal(address(_token1), address(this), type(uint256).max);

        _factory.initialize(address(_nfpManager), address(_veRam), address(_voter), address(0));
        _pool.initialize(address(_factory), address(_nfpManager), address(_veRam), address(_voter), address(_token0), address(_token1), 10_000, 200);
        _pool.initialize(393495975901102234655829);
    }

    function ramsesV2MintCallback(
        uint256 amount0Owed,
        uint256 amount1Owed,
        bytes calldata data
    ) external {
        _token0.transfer(address(_pool), amount0Owed);
        _token1.transfer(address(_pool), amount1Owed);
    }

    function positionHash(
        address owner,
        uint256 index,
        int24 tickLower,
        int24 tickUpper
    ) internal pure returns (bytes32) {
        return keccak256(abi.encodePacked(owner, index, tickLower, tickUpper));
    }

   function testMultipleAttachmentPOC() public {
        uint256 period = block.timestamp / (1 weeks);
        ( 
            uint160 sqrtPriceX96, 
            int24 tick, 
            uint16 observationIndex, 
            uint16 observationCardinality, 
            uint16 observationCardinalityNext, 
            uint8 feeProtocol, 
            bool unlocked
        ) = _pool.slot0();
        int24 tickLower = tick - 132;
        int24 tickUpper = tick + 68;

        // get the boostAmount when using the same index to repeatedly mint
        for (uint i = 0; i < 10; i++) {
            _pool.mint(address(this), 0,  tickLower, tickUpper, 100, 1, "");
        }
        (uint128 boostAmountMintingSameIndex,,,) = _pool.boostInfos(period, positionHash(address(this), 0, tickLower, tickUpper));
        // clear out all the state from this minting such that it doesn't affect the minting below.  In essence, the two operations should functional independently of one another.
        _pool.burn(0, tickLower, tickUpper, 100 * 10, 1);
        _pool.collect(address(this), tickLower, tickUpper, uint128(_token0.balanceOf(address(_pool))), uint128(_token1.balanceOf(address(_pool))));
        vm.startPrank(address(_pool));
        _token0.transfer(address(this), _token0.balanceOf(address(_pool))); // clear the fee balances
        _token1.transfer(address(this), _token1.balanceOf(address(_pool)));
        vm.stopPrank();

        skip(1 weeks); // skip forward a week to ensure the prior period's `totalVeRamAmount` doesn't affect this period's. 
        period = period + 1;

        // get the boostAmount when using different indices to repeatedly mint
        uint128 boostAmountMintingDifferentIndices;
        for (uint i = 0; i < 10; i++) {
            _pool.mint(address(this), i+1,  tickLower, tickUpper, 100, 2, ""); // the VotingEscrow contract is hard coded to return the same balanceOfNFT for every tokenId to illustrate the point.
            (uint128 boostAmountAccumulator,,,) = _pool.boostInfos(period, positionHash(address(this), i+1, tickLower, tickUpper));
            boostAmountMintingDifferentIndices += boostAmountAccumulator;
        }

        // the boostAmount of all the differently indexed positions is > the boost amount when using the same position supplying the same liquidity
        assertGt(uint(boostAmountMintingDifferentIndices), uint(boostAmountMintingSameIndex));
    }
}

Note that the pool in the POC has been initialized similarly to the deployed DEUS/USDC pool which can be found here. Also, note that the MockVotingEscrow contract has been hard coded to return the same balanceOfNFT() (the balance taken from the deployed veRAM contract for tokenId 1 at the time of the test) and isApproverOrOwner() for ease of testing and to illustrate the difference between the two minting strategies.

    function isApprovedOrOwner(address, uint256) external override view returns (bool) {
        return true;
    }
    
    function balanceOfNFT(uint256) external override view returns (uint256) {
        return 21487469130353205716474214;
    }

Impact

High. An attacker can ensure that their newBoostedLiquidity always falls under the boostedLiquidityCap.

Developer Response

Acknowledged, planned to normalize boost of all positions of the same size per address in a future update.

Medium Findings

1. Medium - Treasury fees can be bypassed with repeated calls to `notifyRewardAmount()`

Technical Details

Protocol fees are collected in the pushFees modifier when notifyRewardAmount() in GaugeV2.sol is called, which can be called by anyone at any time. FeeCollector.sol contract’s collectProtocolFees() collects the pool’s protocol fees and then uses the amount retrieved from the pool to calculate the treasury fee amount.

Impact

Medium. Given the low cost of gas on Arbitrum, and the fact that an amount of 0 can be passed to notifyRewardAmount(), the protocol fee of a pool can be kept sufficiently low such that amount0Treasury and amount1Treasury are always 0.

Recommendation

Round the amount0Treasury and amount1Treasury divisions up, so at least 1 unit of the tokens is paid to the treasury when the amount is low enough to round down to 0.

Developer Response

Acknowledged, value of amounts would have to be in the weis or very small to be possible, which gas fees would supercede.

2. Medium - `boostAmount` stays attached to a position after ownership is lost

Technical Details

When a veRamTokenId is attached to a position there is a check to ensure that the msg.sender isApprovedOrOwner of the veRamTokenId. If this check passes, the balance of the NFT is attached to the boostedPosition. However, if the ownership of the veRamTokenId changes, or the position owner is no longer approved, this veRamAmount stays attached to the boostedPosition indefinitely unless the veRamTokenId is explicitly changed, or the liquidity of the position goes to 0.

Impact

Medium. Coupling this attack with the ability to attach multiple positions to the same veRamTokenId an attacker can gain ownership of a new veRamTokenId and attach multiple positions to it, then relinquish the veRamTokenId ownership repeatedly ad infinitum.

Developer Response

Acknowledged, expected behavior that was kept to allow further layers to build on-top to allow seamless transferring. Due to the nature of our rewarding system promoting tighter ticks, this would not be much of an issue as the position will likely need to be withdrawn and re-created to maintain any benefit. Another mitigation is that the boost system operates on epoch-long cycles. For a user to keep the boost, they would need to re-attach at the start of each epoch– which if this transferring of ownership occured, would not be feasible.

3. Medium - Minting, burning, and minting yields higher `boostAmount` than minting

Technical Details

When minting a new position, the pool’s token balances are used to determine hypotheticalLiquidity and therefore the boostedLiquidityCap, veRamBoostAvailable, and positionBoostUsedRatio.

However, when a position is burned, the tokens continue to accrue to the pool until collect() is called by the burner. This means that even though the tokens may be allocated to the burner, and they can retrieve them at any time, they continue to contribute to the boostedLiquidityCap, veRamBoostAvailable, and positionBoostUsedRatio variables when positions are updated. This means that boostedLiquidityCap and veRamBoostAvailable can be inflated, and positionBoostUsedRatio deflated, to any value an attacker would like without supplying additional liquidity.

See this POC illustrating the point in code:

contract AttachTest is Test {

    RamsesV2Pool _pool;
    RamsesV2Factory _factory;
    MockVoter _voter;
    MockNFPManager _nfpManager;
    MockVotingEscrow _veRam;
    MockERC20 _token0;
    MockERC20 _token1;


    function setUp() public {
        _pool = new RamsesV2Pool();
        _factory = new RamsesV2Factory();
        _voter = new MockVoter();
        _nfpManager = new MockNFPManager();
        _veRam = new MockVotingEscrow();
        _token0 = new MockERC20("0", "token_0", 18);
        _token1 = new MockERC20("1", "token_1", 18);

        deal(address(_token0), address(this), type(uint256).max);
        deal(address(_token1), address(this), type(uint256).max);

        vm.label(address(_pool), "_pool");
        vm.label(address(_token0), "_token0");
        vm.label(address(_token1), "_token1");
        vm.label(address(_factory), "_factory");
        vm.label(address(_veRam), "veRam");
        vm.label(address(_nfpManager), "_nfpManager");
        vm.label(address(_voter), "_voter");

        _factory.initialize(address(_nfpManager), address(_veRam), address(_voter), address(0));
        _pool.initialize(address(_factory), address(_nfpManager), address(_veRam), address(_voter), address(_token0), address(_token1), 10_000, 200);
        _pool.initialize(393495975901102234655829);
    }

    function tickSpacingToMaxLiquidityPerTick(int24 tickSpacing) public pure returns (uint128) {
        int24 minTick = (TickMath.MIN_TICK / tickSpacing) * tickSpacing;
        int24 maxTick = (TickMath.MAX_TICK / tickSpacing) * tickSpacing;
        uint24 numTicks = uint24((maxTick - minTick) / tickSpacing) + 1;
        return type(uint128).max / numTicks;
    }

    function testBurnAndMint() public {
        uint256 period = block.timestamp / (1 weeks);
        ( 
            uint160 sqrtPriceX96, 
            int24 tick, 
            uint16 observationIndex, 
            uint16 observationCardinality, 
            uint16 observationCardinalityNext, 
            uint8 feeProtocol, 
            bool unlocked
        ) = _pool.slot0();
        int24 tickLower = tick - 132;
        int24 tickUpper = tick + 68;
        _pool.mint(address(this), 0,  tickLower, tickUpper, tickSpacingToMaxLiquidityPerTick(200), 1, "");
        (uint128 boostAmountPreBurn,,,) = _pool.boostInfos(period, positionHash(address(this), 0, tickLower, tickUpper));
        _pool.burn(0, tickLower, tickUpper, tickSpacingToMaxLiquidityPerTick(200), 1);
        _pool.mint(address(this), 0,  tickLower, tickUpper, tickSpacingToMaxLiquidityPerTick(200), 1, "");
        (uint128 boostAmountPostBurn,,,) = _pool.boostInfos(period, positionHash(address(this), 0, tickLower, tickUpper));
        assertGt(uint(boostAmountPostBurn), uint(boostAmountPreBurn));
    }
}

    function isApprovedOrOwner(address, uint256) external override view returns (bool) {
        return true;
    }
    
    function balanceOfNFT(uint256) external override view returns (uint256) {
        return 21487469130353205716474214;
    }

Impact

Medium. An attacker can bypass the boostedLiquidityCap and veRamBoostAvailable limits.

Recommendation

Maintain separate token balance state variables that should be used by the boosted calculations by subtracting the tokens owed to position burners whenever a position is burned. You could also send the tokens to the burner at the time they are burned, rather than maintaining the balance in the pool.

Developer Response

Acknowledged, we plan on making a poke() function so users can punish bad actors if they game the system this way.

poke() will use current balances in the pool so if the attacker withdrew their tokens then it’ll lower their boost. If the attacker leaves the withdrawable tokens in the pool then everyone else will be getting enlarged boost, negating the enlarged boost the attacker has.

4. Medium - Incorrect math in `left()`

GaugeV2.left() has a mistake in the logic to calculate the remaining time left of the current period.

Technical Details

The line calculating elapsedTime calculates the difference between _blockTimestamp(), with units of seconds, and period, with units of weeks. Subtracting weeks from seconds will result in a nonsensical result, so the two values must have the same units before the difference is calculated.

Impact

Medium. A difference of two values is calculated when they have mismatched units, making the result incorrect.

Recommendation

Modify left() as follows so that the two values used to calculate elapsedTime both have units of seconds:

function left(address token) external view override returns (uint256) {
	uint256 period = _blockTimestamp() / WEEK;
-	uint256 elapsedTime = _blockTimestamp() - period;
+	uint256 elapsedTime = _blockTimestamp() - (period * WEEK);
	return (tokenTotalSupplyByPeriod[period][token] * elapsedTime) / WEEK;
}

Developer Response

Acknowledged, fixed in 7285a1216e5aa13906e2681f20a5451e52a742c3.

Low Findings

1. Low - The first mint in a pool gets 0 `boostAmount` regardless of `veRamTokenId` or liquidity supplied

Technical Details

The boostedLiquidityCap is based on the hypotheticalLiquidity which is based on the pool’s token balances. When a pool is first deployed, it has no liquidity, so the first minter will receive no boostedLiquidity regardless of the size of their mint or veRamTokenId’s balance. This is particularly acute if the minter is minting a large position as is illustrated in the POC below.

See this POC for an illustration of the point in code:

    function testFirstMint() public {
        uint256 period = block.timestamp / (1 weeks);
        ( 
            , 
            int24 tick, 
            , 
            , 
            , 
            , 
        ) = _pool.slot0();
        int24 tickLower = tick - 132;
        int24 tickUpper = tick + 68;
        _pool.mint(address(this), 0,  tickLower, tickUpper, tickSpacingToMaxLiquidityPerTick(200) - 100, 1, "");
        (uint128 boostAmountFirstMint,,,) = _pool.boostInfos(period, positionHash(address(this), 0, tickLower, tickUpper));
        assertEq(uint256(boostAmountFirstMint), 0);
        _pool.mint(address(this), 1,  tickLower, tickUpper, 100, 2, ""); // This could be a new minter, however we're using a different index and veRamTokenId for illustration purposes.
        (uint128 boostAmountSecondMintDifferentPosition,,,) = _pool.boostInfos(period, positionHash(address(this), 1, tickLower, tickUpper));
        assertGt(uint256(boostAmountSecondMintDifferentPosition), 0);
    }

Impact

Low. This should only affect a pool on the first mint. Afterward, there should be liquidity in the pool.

Developer Response

Acknowledged.

2. Low - `GaugeV2.getPeriodReward()` can skip `lastClaimByToken` for a valid claim

lastClaimByToken is used for the last time (< current period) the user claimed rewards. Still, it can be possible to claim the reward for a period without changing the value of lastClaimByToken.

Technical Details

In function, GaugeV2.getPeriodReward(), consider the following:

User wants to claim the reward for period = 13, current period = 14, and lastClaimByToken was made for all the tokens in period 10.

That means the condition comes out to be 10 < period < 13.

          if (
              period > lastClaimByToken[tokens[i]][_positionHash] &&
              period < _blockTimestamp() / WEEK - 1
          ) 

The period for which the rewards were claimed doesn’t lie in the range. Hence, it skips the check and then moves on to the _getReward() call, which lets the user claim a reward for period 13, and lastClaimByToken remained 10.

Well, it should be able to set the lastClaim to that period as it has been passed, and the user can claim the reward for that period later in the function.

Impact

Low.

Recommendation

It’s sufficient to use period < _blockTimestamp() / WEEK to confirm the lastClaim can be made for past period.

Developer Response

Acknowledged.

3. Low - The `rewards` list can grow unbounded in GaugeV2.sol

Technical Details

notifyRewardAmount() is an external function, with no access control modifier, which means anyone can call notifyRewardAmount(). If a token has not been seen before, it is added to the isReward mapping and pushed into the rewards list. This means an attacker could fill the list with a large number of random token addresses. Elsewhere in GaugeV2.sol, such as getPeriodReward(), tokens are passed into the function such that the entire reward list is not iterated through. However, this is not the case in the RamsesRewards.sol contract’s addressEarnedCl() function, where the entire reward list is iterated through.

Impact

Low. Currently, the Gauge’s reward list is used in the addressEarnedCl() function of RamsesRewards.sol, which is a view function, so the impact is not high.

Recommendation

Put a length limit on the reward list, and/or allow the owner to remove reward tokens from the list, and/or access control the notifyRewardAmount() function in GaugeV2.sol.

Developer Response

Acknowledged.

4. Low - `createCLGauge()` code doesn’t match comment

A comment in Voter.createCLGauge() does not match the code.

Technical Details

This comment and a line of code earlier in the function directly conflict with one another.

require(_pool != address(0), "no pool");
...
// gov can create for any pool, even non-Ramses pairs

By requiring _pool != address(0) value of true, governance is limited to only adding gauges to valid RAMSES pairs. This is in contrast to createGauge() for Ramses v1, where the equivalent check requiring isPair to be true is only applied to a non-governor msg.sender.

Impact

Low. Governor does not have the elevated capabilities for adding gauges like RAMSES v1, so the comment or the code is incorrect.

Recommendation

Move the require(_pool != address(0), "no pool"); line of code into the if branch where msg.sender != governor.

Developer Response

Updated the comment in 95192c840e8b2753b821c2f9f29294b12410d1aa

5. Low - Inconsistent first period in GaugeV2

The first period in GaugeV2 will not consistent of a full week of time unless the contract is initialized perfectly on time, which is unlikely. Instead, the first period will have less than 1 week remaining as calculated by the function left() starting from the moment of initialization.

Technical Details

The firstPeriod variable is set during initialization as:

firstPeriod = _blockTimestamp() / WEEK;

This value will be rounded down. The end result of this value rounding down is the same whether the week of firstPeriod is 5% complete or 95% complete during initialization. This rounding down will artificially shorten the time period for the firstPeriod. This may skew the rewards per second during firstPeriod compared to future periods.

Impact

Low. firstPeriod duration will be inconsistent compared to later periods.

Recommendation

Add logic to account for the reduced firstPeriod duration. Or add a comment in the initialization function acknowledging this variation and explaining why it is acceptable.

Developer Response

Acknowledged.

6. Low - Errors in `left()`

Gauge.left() has several minor errors that should be fixed.

Technical Details

The NatSpec for left() references a function that does not exist, getTokenTotalSupplyByPeriod(). The NatSpec should be updated to remove this reference.
The name of the function left() is misleading. The return value sees the elapsedTime value in the numerator, not the remaining time. This means that the return value of left() increases as the period approaches the end of the period, when the function name indicates that the opposite should be true.

Impact

Low. left() function is misleading and should be updated.

Recommendation

Modify left() and the associated comments to fix these errors.

Developer Response

Acknowledged, fixed in 7285a1216e5aa13906e2681f20a5451e52a742c3.

7. Low - No validation of `pool` address in `createGauge()`

createGauge() has an address value function argument that should correlate to the value of a RAMSES pool contract address. This address is never verified to be related to RAMSES in any way, and because createGauge() is permissionless, anyone can call the function and provide an address of their choice. This may cause problems later with RAMSES contracts interacting with an untrusted external contracts.

Technical Details

Like other contracts in RAMSES, RamsesV2GaugeFactory.sol is loosely based on UniswapV3Factory.sol, with the implementation of createGauge() based on createPool(). In Uniswap, anyone can create a pool between two ERC20 tokens. It is unclear whether the same should be true of createGauge(), but there is no access control enforced on this function. The pool address function argument is not verified as a RAMSES pool before it is passed to _deploy(), which also does not validate the pool address value. The result is that a gauge will exist with a pool address that is not a pool, and a malicious party can create a contract that implements the same interface as a RAMSES pool but does not necessarily perform the same actions. There are external calls to the pool address in GaugeV2.sol (such as 1, 2, 3) that may be leveraged into an attack vector, though the specifics have not been fully worked out yet.

Impact

Low. RAMSES will store an untrusted address and make external calls to this address.

Recommendation

Validate the pool function argument before storing it. Modify the code by creating a ramv2Factory variable to store the RamsesV2Factory address and then modify createGauge() as follows:

function createGauge(
-	address pool
+	address token0,
+	address token1,
+	uint24 fee
) external override returns (address gauge) {
+	require(ramv2Factory.getPool[token0][token1][fee] != address(0), "PE");
	require(getGauge[pool] == address(0), "GE");
	gauge = _deploy(voter, nfpManager, feeCollector, pool);
	getGauge[pool] = gauge;
	emit GaugeCreated(pool, gauge);
}

Developer Response

Acknowledged, fixed in 7285a1216e5aa13906e2681f20a5451e52a742c3.

Gas Saving Findings

1. Gas - v1 Gauge.sol `poke()` should cache length before loop

While out of scope, there is a gas savings in RAMSES v1 Gauge.poke().

Technical Details

Gauge.poke() should cache rewards.length before the for loop, then reference the cache length value in the loop, to achieve gas savings. Otherwise the length of the rewards state variable is checked on each iteration of the loop.

This finding was automatically identified by slither.

Impact

Gas savings.

Recommendation

Modify the for loop to cache the length value before the loop.

- for (uint256 i; i < rewards.length; ++i) {
uint256 rlength = rewards.length;
+ for (uint256 i; i < rlength; ++i) {

2. Gas - `_find_time_user_epoch()` loop iterations can be reduced

VotingEscrow._find_time_user_epoch() has binary search logic similar to that found in VotingEscrow.vy in Curve Finance. The for loop in this function can be made more efficient.

Technical Details

VotingEscrow.vy in Curve has a function find_block_epoch() which implements binary search using a for loop that repeats 128 times. RAMSES has a similar VotingEscrow._find_time_user_epoch() function that implements binary search using a for loop that repeats 256 times. The RAMSES VotingEscrow._find_time_user_epoch() implementation is in contrast to the RAMSES implementation of VotingEscrow._balanceOfAtNFT(), which loops 128 times like Curve. There is no need for VotingEscrow._find_time_user_epoch() to loop 256 times, it can stop at 128.

Impact

Gas savings.

Recommendation

Modify the for loop in _find_time_user_epoch() to loop only 128 times.

3. Gas - Move logic into if statement

A line in Voter._updateFor() can be moved into the branching logic to save gas when a specific branch is skipped.

Technical Details

_supplied is only needed in the if branch, so it can be set inside that branch.

function _updateFor(address _gauge) internal {
	address _pool = poolForGauge[_gauge];
-	uint256 _supplied = weights[_pool];
	uint256 _supplyIndex = supplyIndex[_gauge];

	// only new pools will have 0 _supplyIndex
	if (_supplyIndex > 0) {
+		uint256 _supplied = weights[_pool];
		uint256 _index = index; // get global index0 for accumulated distro

Impact

Gas savings.

Recommendation

Move variable declaration into branching logic.

4. Gas - `periodSecondsPerBoostedLiquidityOutsideBeforeX128` and `periodSecondsPerLiquidityOutsideBeforeX128` are 0 and can be removed from subtraction

Technical Details

In cross() periodSecondsPerLiquidityOutsideBeforeX128 and periodSecondsPerBoostedLiquidityOutsideBeforeX128 must be 0 for the if logic to be executed. In this case, their subtraction does nothing to contribute to the final periodSecondsPerLiquidityOutsideX128 and periodSecondsPerBoostedLiquidityOutsideX128 values.

Impact

Gas savings.

Recommendation

Remove the variables from the subtraction.

5. Gas - `ERC721PermitUpgradeable` inherits from `Initializable` twice

There is duplicate inheritance in ERC721PermitUpgradeable, meaning one of these instances can be removed.

Technical Details

ERC721PermitUpgradeable inherits from Initializable explicitly. However, ERC721Upgradeable already inherits from Initializable.

Impact

Gas savings.

Recommendation

Remove the explicit Initializable inheritance.

6. Gas - `positionLiquidity - params.liquidity` is calculated twice

Duplicate calculation of a value can be optimized to save gas.

Technical Details

position.liquidity is stored as positionLiquidity - params.liquidity. This is recomputed to check if the liquidity difference is 0 and unset the veRamTokenId.

Impact

Gas savings.

Recommendation

Check if position.liquidity is 0 rather than re-computing positionLiquidity - params.liquidity.

7. Gas - Gas can be saved calling a different `periodEarned()` in GaugeV2.sol

Two versions of the periodEarned() function are available and calling the other version of the function can save gas.

Technical Details

Currently, in earned() periodEarned(period, token, tokenId) is called to accumulate the reward. This periodEarned() function re-computes the tickLower and tickUpper which are already known at the time periodEarned() is called in earned().

Impact

Gas savings.

Recommendation

Use the periodEarned() that includes tickLower and tickUpper as parameters in earned() when accumulating the rewards in earned().

Informational Findings

1. Informational - Restrict reward claim for current epoch

The current implementation of GaugeV2 allows the user to claim the reward for the current epoch using the function getReward() which does an internal call to _getAllRewards which lets the user claim the reward for the current epoch.

Technical Details

Since all the important (rewards deciding) variables for the current epoch get set at the start of the next epoch, it is crucial to not let the user claim the reward for the current epoch. Additionally, the reward that the user is claiming for the current week turns out to be an arbitrary value calculated using a fixed value of boostedInRange as 1 WEEK. Even if the user claims the reward for the current week, his/her rewards are still accumulating which the user can’t claim as those rewards become available in the next epoch. Then it is better to restrict users to claim rewards for the current epoch.

Impact

Informational.

Recommendation

In _getAllRewards():

    function _getAllRewards(
        address owner,
        uint256 index,
        int24 tickLower,
        int24 tickUpper,
        address[] memory tokens,
        address receiver
    ) internal {
        bytes32 _positionHash = positionHash(
            owner,
            index,
            tickLower,
            tickUpper
        );
        uint256 currentPeriod = _blockTimestamp() / WEEK;
        uint256 lastClaim;
        for (uint256 i = 0; i < tokens.length; ++i) {
            lastClaim = Math.max(
                lastClaimByToken[tokens[i]][_positionHash],
                firstPeriod
            );
            
            for (
                uint256 period = lastClaim;
-                period <= currentPeriod;
+               period < currentPeriod;
                ++period
            ) {
                _getReward(
                    period,
                    tokens[i],
                    owner,
                    index,
                    tickLower,
                    tickUpper,
                    _positionHash,
                    receiver
                );
            }
            lastClaimByToken[tokens[i]][_positionHash] = currentPeriod - 1;
        }
    }

2. Informational - `initialize` should emit event for variable set

As initialize is used to set the important variables in the beacon proxy pattern, it doesn’t emit an event for setting up those important variables.

Technical Details

Ideally, the following should trigger events.

FeeCollector.initialize() should emit TreasuryChanged.
RamsesV2Factory.initialize() should emit ImplementationChanged

Impact

Informational.

Recommendation

Add event emission event for setting them for the first time, as Uniswap v3 follows this practice.

3. Informational - `_switchAttachment` shouldn’t allow switch if `position.liquidity == 0`

One of the protocol invariants is to detach veRamTokenId (setting it to 0) from pool/nfpManager if the liquidity of the position becomes zero, but _switchAttachment could be used to attach a veRamTokenId even if the position has no liquidity.

Technical Details

Once a user decreases all the liquidity from its nfpManager position, the veRamTokenId from both the pool and nfpManager position gets detached (becomes 0). But if the user calls _switchAttachment it will set veRamTokenId in nfpManager, but in the pool, the user attachedVeRamId remains zero. (nfpManager.switchAttachment() -> pool.burn() -> _updateLiquidity() which only updates veRamTokenId, if newLiquidity > 0).

This can make the pool and nfpManager contract out of sync for a user position.

Impact

Informational.

Recommendation

    function switchAttachment(
        uint256 tokenId,
        uint256 veRamTokenId
    ) external override isAuthorizedForToken(tokenId) {
        if (veRamTokenId != 0) {
            require(
                IVotingEscrow(veRam()).isApprovedOrOwner(
                    msg.sender,
                    veRamTokenId
                ),
                "veRam not approved"
            );
        }

        Position storage position = _positions[tokenId];

+      require(position.liquidity > 0, "blah");
        PoolAddress.PoolKey memory poolKey = _poolIdToPoolKey[position.poolId];

        IRamsesV2Pool pool = IRamsesV2Pool(
            PoolAddress.computeAddress(factory, poolKey)
        );
        
        emit SwitchAttachment(tokenId, position.veRamTokenId, veRamTokenId);

        position.veRamTokenId = veRamTokenId;

        pool.burn(
            tokenId,
            position.tickLower,
            position.tickUpper,
            0,
            veRamTokenId
        );
    }

4. Informational - Incorrect NatSpec comment in `ProtocolActions` Library

Event CollectProtocol has an incorrect comment.

Technical Details

CollectProtocol event is emitted when feeCollector calls the collectProtocol function of RamsesV2Pool.sol, as the function has a modifier onlyFeeCollector which means it can only be called by feeCollector.

Impact

Informational.

Recommendation

-    /// @notice Emitted when the collected protocol fees are withdrawn by the factory owner
+  /// @notice Emitted when the collected protocol fees are withdrawn by the fee collector
    /// @param sender The address that collects the protocol fees
    /// @param recipient The address that receives the collected protocol fees
    /// @param amount0 The amount of token0 protocol fees that is withdrawn
    /// @param amount0 The amount of token1 protocol fees that is withdrawn
    event CollectProtocol(address indexed sender, address indexed recipient, uint128 amount0, uint128 amount1);

5. Informational - Revert doesn’t contain error message

Failed operations in the smart contracts in scope are reverted with error messages provided in the require statement, making it easier to debug the reason for the failure of the transaction.

Technical Details

Revert statement reverts without error message in the following functions.

RamsesV2Pool.sol:
- onlyFeeCollector()
- mint()
RamsesV2Factory.sol:
- enableFeeAmount()
NonfungiblePositionManager.sol:
- tokenURI()
- decreaseLiquidity()
SwapRouter.sol:
- ramsesV2SwapCallback()
- exactOutputInternal()

Impact

Informational.

Recommendation

Use revert string, to make transaction reverts easily detectable.

6. Informational - inconsistency in preventing implementation initialization

Technical Details

There needs to be more consistent behavior in the constructor of implementation contracts. The following contracts use _disableInitializers(); to disable initialization of implementation (which is good):

GuageV2.sol
FeeCollector.sol
RamsesLens.sol

But other contracts follow constructor() initializer {} (which does the same thing, but it is recommended to use _disableInitializers for implementations)

Impact

Informational.

Recommendation

Use consistent behavior to prevent initialization of implementation. Also, _disableInitializers is more gas efficient.

7. Informational - Imports are unused

Technical Details

Various imports throughout the codebase are not used and can be removed.

Impact

Informational

Recommendation

Remove the imports.

8. Informational - Contract without proxy can be simplified

RamsesDeployer.sol for RAMSES v2 is not deployed behind a proxy. This is in contrast to the nearly identical RamsesDeployer.sol for RAMSES v1, which is deployed behind a contract. The v2 contract could be simplified because it contains proxy artifacts.

Technical Details

Several proxy artifacts in RamsesDeployer.sol can be modified because it is not behind a proxy:

The file imported from @openzeppelin/contracts-upgradeable can be changed to the @openzeppelin/contracts version of the file.
Initializer is not necessary.
initialize() can be replaced by the contract constructor.

Impact

Informational.

Recommendation

Remove proxy artifacts when a contract is not deployed behind a proxy.

9. Informational - Whitelisted tokens for gauges cannot be removed

Voter.whitelist() allows specific tokens to be whitelisted so that non-governance users can create a gauge for pools with whitelisted tokens. There is no way to reverse the process and remove a token from the whitelist. The goal of this may be to decrease the power of the multisig over the protocol, but if there is a vulnerability in a whitelisted token, the lack of a blacklist() function to remove a token from the whitelist may make it more difficult to protect the protocol from certain risks.

Technical Details

There is no way to reverse the action of the whitelist() operation in Voter.sol. If there is a token that should be removed from the whitelist, the Voter contract (which is deployed behind a proxy) may need to be replaced. Adding a function to reverse the whitelisting of tokens can improve the mitigation of future threats if a trusted token contract is maliciously or incompatibly upgraded.

Impact

Informational.

Recommendation

Add a way to reverse the action of whitelist(). This function could be accessible to only the emergencyCouncil role, which may have a higher threshold of activation to the governor role.

10. Informational - Emergency council identical to governor in Voter.sol

The RAMSES docs have a section titled “The Path Towards Decentralization”, but in summary the docs say the protocol is working on this aspect of the protocol. One example is governor and the emergencyCouncil of Voter.sol are identical values, with the RAMSES multisig assigned to those two state variables. This choice of using the same multisig for the two values is different from other Solidly forks.

Technical Details

Voter.sol has a governor role and an emergencyCouncil role. In the on-chain contract, the same RAMSES multisig is set for these two different roles. In other Solidly fork implementations with the emergencyCouncil role, such as Velodrome on Optimism and PearlFi on Polygon, these roles are assigned to different multisigs. Specifically, the emergencyCouncil multisig has a higher threshold than the governance multisig, suggesting a design choice where controlling the uptime of the protocol requires cooperation from more signers than adding gauges to the protocol.

This is a design choice and RAMSES may have decided that the current approach is best, but without clear documentation on this choice, the current settings make the RAMSES multisig a centralized source of power over the full protocol.

Impact

Informational.

Recommendation

Consider creating a new emergencyCouncil multisig for the protocol with a higher signer threshold compared to the main multisig.

11. Informational - On-chain contracts using different library versions

Some of the on-chain contracts are using older versions of library code. These differences are minor and unlikely to cause issues, but using consistent code across all contracts in the protocol could remove some risk by reducing the amount of unique code deployed.

Technical Details

Some of the on-chain code does not match the contract versions reviewed during this audit. Specifically, the on-chain Oracle.sol deployment at 0xf70c9C4F6281C0750d68da8878894b1235cb6020 has some minor differences in 3 dependencies, States.sol, LiquidityMath.sol, and Tick.sol, compared to the code reviewed in this audit.

Similarly, Tick.sol deployed at 0xc989D669831Cd5258369CB0Dce7752CbfE7303E8 and ProtocolActions.sol deployed at 0xa67f82621540017a679153423CA0B8a1b4518B49 have different versions of the State.sol library dependency compared to the version of State.sol in this audit.

Impact

Informational.

Recommendation

Consider upgrading all code to use the same version of libraries.

12. Informational - Reduce rounding error inaccuracy

GaugeV2.rewardRate() includes two division operations that can be combined into one. This would reduce the inaccuracy due to two rounding down operations.

Technical Details

The two division operations can be reduced to one to minimize error created by the rounding down inherent in a solidity division operation.

function rewardRate(address token) external view returns (uint256) {
	uint256 period = _blockTimestamp() / WEEK;
-	return (tokenTotalSupplyByPeriod[period][token] * 4) / 10 / WEEK;
+	return (tokenTotalSupplyByPeriod[period][token] * 4) / (10 * WEEK);
}

Impact

Informational.

Recommendation

Remove a division operation to reduce rounding inaccuracy.

Developer Response

Acknowledged, fixed in 7285a1216e5aa13906e2681f20a5451e52a742c3.

13. Informational - Beacon proxy inconsistency

There is a slight inconsistency in how the beacon proxy is configured for pools and how they are configured for gauges.

Technical Details

RamsesV2PoolDeployer uses the value keccak256(abi.encode()) for the beacon proxy creation while RamsesV2GaugeDeployer uses keccak256(abi.encodePacked()). These contracts perform almost the exact same task, so the same code logic should be used.

Impact

Informational.

Recommendation

Use a consistent ABI packing for similar functions. Consider using abi.encode() over abi.encodePacked() to avoid collisions, even though there are no dynamic types provided as input to the ABI encoding currently.

14. Informational - `STATES_SLOT` can accidentally match a known pre-image

Technical Details

By calculating STATES_SLOT = keccak256("states.storage") using a string value, the first pre-image of STATES_SLOT is known (“states.storage”), which makes it accidentally match the known pre-image (“states.storage”). Openzeppelin and all proxy standards derive their custom storage slot in this way. Ref

Impact

Informational.

Recommendation

It is general practice to refrain from using pre-images while fixing important storage slots.
```
bytes32 STATES_SLOT = keccak256("states.storage") - 1
```
Make STATES_SLOT a constant variable.

By doing so, the first pre-image of STATES_SLOT becomes unknown, enhancing the storage slot’s security.

15. Informational - First period has default zero value for `startTick` and `previousPeriod`

RamsesV2Pool._advancePeriod() updates the pool state values when advancing to the next period. startTick and previousPeriod are values in the pool state that are set at the start of a new period, but because these values are only set when there is a previous period, the first period does not have these values set. Therefore, the first period will store the default zero value for startTick and previousPeriod, which makes handling these values potentially more difficult for the special case of the first period.

Technical Details

The implementation of RamsesV2Pool._advancePeriod() primarily updates the values for states.periods[_lastPeriod], or the state of the last period. Only one line of code updates the current period value. Because _advancePeriod() is first called in initialize(), the initial _lastPeriod value of zero will be meaningless, but it will have no values set for startTick and previousPeriod, so these values will remain zero. The first real period is the 1st period (not the 0th period). Any loop that iterates through the period states should consider this, but there is no comment to clarify this is how the period values are handled.

Impact

Informational.

Recommendation

Clarify that the 0 index of states.periods[] should be ignored and the first period has an index of 1. This should be documented in the NatSpec for _advancePeriod().

16. Informational - Forked Uniswap v3 code uses OZ 3.4.1 not 3.4.2

Uniswap v3 Periphery depends on OpenZeppelin contracts version 3.4.2-solc-0.7. The RAMSES v2-periphery/ directory, which is a direct fork of the Uniswap code, uses OZ version 3.4.1.

Technical Details

The changes made between 3.4.2 and 3.4.1 are minimal, which just one commit made in TimelockController, which is not directly used in the v2-periphery/ directory. However, if the goal is to maintain maximum similarity to the original Uniswap, this dependency on OpenZeppelin in the v2-periphery/ directory should be upgraded to OZ 3.4.2.

Impact

Informational.

Recommendation

Upgrade v2-periphery files to use OZ 3.4.2.

17. Informational - Improve naming choices

There are several name choices in the codebase that could be improved.

Technical Details

Several naming choices that could be improved include:

RamsesV2Pool.sol has two functions named “initialize”. The second function sets the initial price for the pool and may be better named “setInitialPoolPrice” to avoid confusion. The function name “initialize” is generally used for a single function in an implementation contract sitting behind a proxy. This function can only be called once and sets initial values similar to how a constructor would work in a non-proxy context. But in RamsesV2Pool.sol, the second initialize function can be called more than once because it lacks an initializer modifier.
PeripheryUpgradeable.sol is a renamed version of PeripheryImmutableState.sol in Uniswap v3. The interface for PeripheryUpgradeable.sol still has the original name of IPeripheryImmutableState.sol, which does not match the contract implementing the interface file. PeripheryUpgradeable.sol is a modified version of Uniswap’s PeripheryImmutableState.sol. But the interface that is implemented in the RAMSES file is not renamed to match the contract name. Instead, the original IPeripheryImmutableState interface name remains.
Although out of scope, the _gauges function argument in Voter.initialize() would be better named _gaugefactory, because the variable name _gauges is used elsewhere in the contract to refer to a different variable.

Impact

Informational.

Recommendation

Improve naming choices in several places.

18. Informational - Remove library functions that are never used

At least one library function does not get called in the codebase and can be removed.

Technical Details

checkTicks() is declared at the end of Tick.sol but is never called. The only place where the code acknowledges this function is a comment in collect() with the word “checkTicks”. checkTicks() could be called in RamsesV2Pool.snapshotCumulativesInside() to replace the existing tick checks, but this may only make sense if checkTicks() gets called in more than one location.

Impact

Informational.

Recommendation

Remove unused functions and comments referencing such functions.

19. Informational - RamsesV2Pool view functions don’t return all struct values

The design may be intentional, but several view functions in RamsesV2Pool that only have the purpose of returning custom struct values omit some values stored in the struct.

Technical Details

One specific example of this is ticks() that does not return:

cleanUnusedSlot
cleanUnusedSlot2
periodSecondsPerLiquidityOutsideX128
periodSecondsPerBoostedLiquidityOutsideX128

Another example is boostInfos(uint256, bytes32) which returns values from a BoostInfo struct but does not return secondsPerLiquidityPeriodStartX128 or secondsPerBoostedLiquidityPeriodStartX128.

A third example is observations() which returns all values from the Observation struct except for boostedInRange.

Impact

Informational.

Recommendation

When the function’s only goal is to return a struct, consider documenting the intentional omission of certain values from the return values to avoid assumptions that the omissions may be a mistake.

Final remarks

The RAMSES team was made aware of the Velodrome Spearbit audit findings which were also applicable to RAMSES at the frozen commit. However, these findings were left out of this report for brevity’s sake such as to avoid duplicate reporting.

The RAMSES team should focus on adding more robust testing, particularly of the interactions between the forked code and new code, as well as fork, fuzz, and invariant testing, as many of the issues reported could have been caught with more robust unit tests. While much of the RAMSES code in this review is forked from Uniswap v3 and uses Uniswap v3 tests, the modifications to the forked code do not have any tests. For example, there were limited, or no unit tests for the new veRamTokenId value used in pools. The lack of unit tests in modified code and the possibility that the assumptions inherited from the forked code are not deeply understood or considered in the modified design could lead to issues in the way that the forked code is integrated with novel code.

yAudit RAMSES Review

Table of Contents

Review Summary

Scope

Code Evaluation Matrix

Findings Explanation

Critical Findings

High Findings

1. High - Minting with different position indices yields a higher total boostAmount than minting with the same index

Technical Details

Impact

Developer Response

Medium Findings

1. Medium - Treasury fees can be bypassed with repeated calls to notifyRewardAmount()

Technical Details

Impact

Recommendation

Developer Response

2. Medium - boostAmount stays attached to a position after ownership is lost

Technical Details

Impact

Developer Response

3. Medium - Minting, burning, and minting yields higher boostAmount than minting

Technical Details

Impact

Recommendation

Developer Response

4. Medium - Incorrect math in left()

Technical Details

Impact

Recommendation

Developer Response

Low Findings

1. Low - The first mint in a pool gets 0 boostAmount regardless of veRamTokenId or liquidity supplied

Technical Details

Impact

Developer Response

2. Low - GaugeV2.getPeriodReward() can skip lastClaimByToken for a valid claim

Technical Details

Impact

Recommendation

Developer Response

3. Low - The rewards list can grow unbounded in GaugeV2.sol

Technical Details

Impact

Recommendation

Developer Response

4. Low - createCLGauge() code doesn’t match comment

Technical Details

Impact

Recommendation

Developer Response

5. Low - Inconsistent first period in GaugeV2

Technical Details

Impact

Recommendation

Developer Response

6. Low - Errors in left()

Technical Details

Impact

Recommendation

Developer Response

7. Low - No validation of pool address in createGauge()

Technical Details

Impact

Recommendation

Developer Response

Gas Saving Findings

1. Gas - v1 Gauge.sol poke() should cache length before loop

Technical Details

Impact

Recommendation

2. Gas - _find_time_user_epoch() loop iterations can be reduced

Technical Details

Impact

Recommendation

3. Gas - Move logic into if statement

Technical Details

Impact

Recommendation

1. High - Minting with different position indices yields a higher total `boostAmount` than minting with the same index

1. Medium - Treasury fees can be bypassed with repeated calls to `notifyRewardAmount()`

2. Medium - `boostAmount` stays attached to a position after ownership is lost

3. Medium - Minting, burning, and minting yields higher `boostAmount` than minting

4. Medium - Incorrect math in `left()`

1. Low - The first mint in a pool gets 0 `boostAmount` regardless of `veRamTokenId` or liquidity supplied

2. Low - `GaugeV2.getPeriodReward()` can skip `lastClaimByToken` for a valid claim

3. Low - The `rewards` list can grow unbounded in GaugeV2.sol

4. Low - `createCLGauge()` code doesn’t match comment

6. Low - Errors in `left()`

7. Low - No validation of `pool` address in `createGauge()`

1. Gas - v1 Gauge.sol `poke()` should cache length before loop

2. Gas - `_find_time_user_epoch()` loop iterations can be reduced

4. Gas - `periodSecondsPerBoostedLiquidityOutsideBeforeX128` and `periodSecondsPerLiquidityOutsideBeforeX128` are 0 and can be removed from subtraction

5. Gas - `ERC721PermitUpgradeable` inherits from `Initializable` twice

6. Gas - `positionLiquidity - params.liquidity` is calculated twice

7. Gas - Gas can be saved calling a different `periodEarned()` in GaugeV2.sol

2. Informational - `initialize` should emit event for variable set

3. Informational - `_switchAttachment` shouldn’t allow switch if `position.liquidity == 0`

4. Informational - Incorrect NatSpec comment in `ProtocolActions` Library