Dinero Strategies V1 - Jigsaw Finance


Prepared by:

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HALBORN

Last Updated 02/26/2025

Date of Engagement: December 26th, 2024 - December 27th, 2024

Summary

100% of all REPORTED Findings have been addressed

All findings

3

Critical

0

High

0

Medium

0

Low

1

Informational

2


1. Introduction

Jigsaw Protocol engaged Halborn to conduct a security assessment on their smart contracts beginning on December 26th, 2024 and ending on December 27th, 2024. The security assessment was scoped to the smart contracts provided to Halborn. Commit hashes and further details can be found in the Scope section of this report.


The Jigsaw Protocol codebase in scope mainly consists of a smart contract that enables users of the Jigsaw Protocol to invest their collateral into the Dinero protocol to generate yield and rewards.

2. Assessment Summary

Halborn was provided 2 days for the engagement and assigned 1 full-time security engineer to review the security of the smart contracts in scope. The engineer is a blockchain and smart contract security expert with advanced penetration testing and smart contract hacking skills, and deep knowledge of multiple blockchain protocols.

The purpose of the assessment is to:

    • Identify potential security issues within the smart contracts.

    • Ensure that smart contract functionality operates as intended.


In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which were addressed by the Jigsaw Protocol team:

    • Consider removing either tokenIn or weth and use a single reference consistently throughout the contract. Alternatively, ensure that tokenIn is always equal to weth. Add explicit documentation to clarify the token usage.

    • Update the Natspec documentation for the initialize() function in the DineroStrategy contract to accurately describe the function's tokenOut parameter.

    • Consider replacing all revert strings with custom errors.


3. Test Approach and Methodology

Halborn performed a combination of manual review of the code and automated security testing to balance efficiency, timeliness, practicality, and accuracy in regard to the scope of this assessment. While manual testing is recommended to uncover flaws in logic, process, and implementation; automated testing techniques help enhance coverage of smart contracts and can quickly identify items that do not follow security best practices.

The following phases and associated tools were used throughout the term of the assessment:

    • Research into architecture, purpose and use of the platform.

    • Smart contract manual code review and walkthrough to identify any logic issue.

    • Thorough assessment of safety and usage of critical Solidity variables and functions in scope that could led to arithmetic related vulnerabilities.

    • Local testing with custom scripts (Foundry).

    • Fork testing against main networks (Foundry).

    • Static analysis of security for scoped contract, and imported functions (Slither).

4. RISK METHODOLOGY

Every vulnerability and issue observed by Halborn is ranked based on two sets of Metrics and a Severity Coefficient. This system is inspired by the industry standard Common Vulnerability Scoring System.
The two Metric sets are: Exploitability and Impact. Exploitability captures the ease and technical means by which vulnerabilities can be exploited and Impact describes the consequences of a successful exploit.
The Severity Coefficients is designed to further refine the accuracy of the ranking with two factors: Reversibility and Scope. These capture the impact of the vulnerability on the environment as well as the number of users and smart contracts affected.
The final score is a value between 0-10 rounded up to 1 decimal place and 10 corresponding to the highest security risk. This provides an objective and accurate rating of the severity of security vulnerabilities in smart contracts.
The system is designed to assist in identifying and prioritizing vulnerabilities based on their level of risk to address the most critical issues in a timely manner.

4.1 EXPLOITABILITY

Attack Origin (AO):
Captures whether the attack requires compromising a specific account.
Attack Cost (AC):
Captures the cost of exploiting the vulnerability incurred by the attacker relative to sending a single transaction on the relevant blockchain. Includes but is not limited to financial and computational cost.
Attack Complexity (AX):
Describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Includes but is not limited to macro situation, available third-party liquidity and regulatory challenges.
Metrics:
EXPLOITABILITY METRIC (mem_e)METRIC VALUENUMERICAL VALUE
Attack Origin (AO)Arbitrary (AO:A)
Specific (AO:S)
1
0.2
Attack Cost (AC)Low (AC:L)
Medium (AC:M)
High (AC:H)
1
0.67
0.33
Attack Complexity (AX)Low (AX:L)
Medium (AX:M)
High (AX:H)
1
0.67
0.33
Exploitability EE is calculated using the following formula:

E=meE = \prod m_e

4.2 IMPACT

Confidentiality (C):
Measures the impact to the confidentiality of the information resources managed by the contract due to a successfully exploited vulnerability. Confidentiality refers to limiting access to authorized users only.
Integrity (I):
Measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of data stored and/or processed on-chain. Integrity impact directly affecting Deposit or Yield records is excluded.
Availability (A):
Measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. This metric refers to smart contract features and functionality, not state. Availability impact directly affecting Deposit or Yield is excluded.
Deposit (D):
Measures the impact to the deposits made to the contract by either users or owners.
Yield (Y):
Measures the impact to the yield generated by the contract for either users or owners.
Metrics:
IMPACT METRIC (mIm_I)METRIC VALUENUMERICAL VALUE
Confidentiality (C)None (I:N)
Low (I:L)
Medium (I:M)
High (I:H)
Critical (I:C)
0
0.25
0.5
0.75
1
Integrity (I)None (I:N)
Low (I:L)
Medium (I:M)
High (I:H)
Critical (I:C)
0
0.25
0.5
0.75
1
Availability (A)None (A:N)
Low (A:L)
Medium (A:M)
High (A:H)
Critical (A:C)
0
0.25
0.5
0.75
1
Deposit (D)None (D:N)
Low (D:L)
Medium (D:M)
High (D:H)
Critical (D:C)
0
0.25
0.5
0.75
1
Yield (Y)None (Y:N)
Low (Y:L)
Medium (Y:M)
High (Y:H)
Critical (Y:C)
0
0.25
0.5
0.75
1
Impact II is calculated using the following formula:

I=max(mI)+mImax(mI)4I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}

4.3 SEVERITY COEFFICIENT

Reversibility (R):
Describes the share of the exploited vulnerability effects that can be reversed. For upgradeable contracts, assume the contract private key is available.
Scope (S):
Captures whether a vulnerability in one vulnerable contract impacts resources in other contracts.
Metrics:
SEVERITY COEFFICIENT (CC)COEFFICIENT VALUENUMERICAL VALUE
Reversibility (rr)None (R:N)
Partial (R:P)
Full (R:F)
1
0.5
0.25
Scope (ss)Changed (S:C)
Unchanged (S:U)
1.25
1
Severity Coefficient CC is obtained by the following product:

C=rsC = rs

The Vulnerability Severity Score SS is obtained by:

S=min(10,EIC10)S = min(10, EIC * 10)

The score is rounded up to 1 decimal places.
SeverityScore Value Range
Critical9 - 10
High7 - 8.9
Medium4.5 - 6.9
Low2 - 4.4
Informational0 - 1.9

5. SCOPE

Files and Repository
(a) Repository: jigsaw-strategies-v1
(b) Assessed Commit ID: e04cbeb
(c) Items in scope:
  • src/dinero/DineroStrategy.sol
  • src/dinero/interfaces/IAutoPxEth.sol
  • src/dinero/interfaces/IPirexEth.sol
↓ Expand ↓
Out-of-Scope: Third party dependencies and economic attacks.
Remediation Commit ID:
Out-of-Scope: New features/implementations after the remediation commit IDs.

6. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

0

Low

1

Informational

2

Security analysisRisk levelRemediation Date
Inconsistent token usage between WETH and TokenInLowSolved - 01/17/2025
Incorrect Natspec documentationInformationalSolved - 02/17/2025
Use of revert strings over custom errorsInformationalAcknowledged - 02/07/2025

7. Findings & Tech Details

7.1 Inconsistent token usage between WETH and TokenIn

//

Low

Description

The contract demonstrates inconsistent usage between tokenIn and weth variables, which could lead to confusion and potential issues:


1. While the contract documentation indicates WETH is used as the input token, the contract maintains separate declarations for tokenIn and weth.

/**
* @notice The wETH token is utilized as the input token, which is later unwrapped to ETH and re-wrapped to
* facilitate Dinero investments.
*/
address public override tokenIn;

/**
* @notice wETH address used for strategy
*/
IWETH9 public weth;

2. The deposit() function validates _asset against tokenIn, but then uses the weth address for withdrawals:

function deposit(
    address _asset,
    uint256 _amount,
    address _recipient,
    bytes calldata
) external override nonReentrant onlyValidAmount(_amount) onlyStrategyManager returns (uint256, uint256) {
    require(_asset == tokenIn, "3001");
    uint256 balanceBefore = IERC20(tokenOut).balanceOf(_recipient);

    IHolding(_recipient).transfer({ _token: _asset, _to: address(this), _amount: _amount });

    // Swap wETH to ETH.
    weth.withdraw(_amount);
    // Deposit ETH to mint pxETH and stakes pxETH for autocompounding.
    pirexEth.deposit{ value: _amount }({ receiver: _recipient, shouldCompound: true });

    uint256 shares = IERC20(tokenOut).balanceOf(_recipient) - balanceBefore;
    recipients[_recipient].investedAmount += _amount;
    recipients[_recipient].totalShares += shares;

    // Mint Strategy's receipt tokens to allow later withdrawal.
    _mint({
        _receiptToken: receiptToken,
        _recipient: _recipient,
        _amount: shares,
        _tokenDecimals: IERC20Metadata(tokenOut).decimals()
    });

    // Register `_recipient`'s deposit operation to generate jigsaw rewards.
    jigsawStaker.deposit({ _user: _recipient, _amount: shares });

    emit Deposit({
        asset: _asset,
        tokenIn: tokenIn,
        assetAmount: _amount,
        tokenInAmount: _amount,
        shares: shares,
        recipient: _recipient
    });
    return (shares, _amount);
}

3. The withdraw() function shows similar inconsistency by using tokenIn for transfers and balance checks, while also referencing weth:

function withdraw(
    uint256 _shares,
    address _recipient,
    address _asset,
    bytes calldata
) external override nonReentrant onlyStrategyManager returns (uint256, uint256) {
    require(_asset == tokenIn, "3001");
    require(_shares <= IERC20(tokenOut).balanceOf(_recipient), "2002");

    WithdrawParams memory params = WithdrawParams({
        shareRatio: 0,
        investment: 0,
        balanceBefore: 0,
        balanceAfter: 0,
        balanceDiff: 0,
        performanceFee: 0
    });

    // Calculate the ratio between all user's shares and the amount of shares used for withdrawal.
    params.shareRatio = OperationsLib.getRatio({
        numerator: _shares,
        denominator: recipients[_recipient].totalShares,
        precision: IERC20Metadata(tokenOut).decimals(),
        rounding: OperationsLib.Rounding.Floor
    });

    // Burn Strategy's receipt tokens used for withdrawal.
    _burn({
        _receiptToken: receiptToken,
        _recipient: _recipient,
        _shares: _shares,
        _totalShares: recipients[_recipient].totalShares,
        _tokenDecimals: IERC20Metadata(tokenOut).decimals()
    });

    // To accurately compute the protocol's fees from the yield generated by the strategy, we first need to
    // determine the percentage of the initial investment being withdrawn. This allows us to assess whether any
    // yield has been generated beyond the initial investment.
    params.investment =
        (recipients[_recipient].investedAmount * params.shareRatio) / (10 ** IERC20Metadata(tokenOut).decimals());

    params.balanceBefore = IERC20(tokenIn).balanceOf(_recipient);

    // Redeem pxETH via the AutoPirexEth contract using the recipient's `IHolding` contract.
    (bool success, bytes memory returnData) = IHolding(_recipient).genericCall({
        _contract: address(autoPirexEth),
        _call: abi.encodeCall(IAutoPxEth.redeem, (_shares, address(this), _recipient))
    });

    // Ensure the external call was successful and decode any potential revert reason.
    require(success, OperationsLib.getRevertMsg(returnData));

    // Decode the returned data to get the amount of pxETH withdrawn from the AutoPirexEth contract.
    uint256 pxEthWithdrawn = abi.decode(returnData, (uint256));

    // Use the PirexEth contract to instantly redeem the withdrawn pxETH for ETH.
    (uint256 postFeeAmount,) = pirexEth.instantRedeemWithPxEth(pxEthWithdrawn, address(this));

    // Swap ETH back to WETH.
    weth.deposit{ value: postFeeAmount }();

    // Transfer WETH to the `_recipient`.
    IERC20(tokenIn).safeTransfer(_recipient, postFeeAmount);

    // Take protocol's fee if any.
    params.balanceDiff = IERC20(tokenIn).balanceOf(_recipient) - params.balanceBefore;
    (params.performanceFee,,) = _getStrategyManager().strategyInfo(address(this));
    if (params.balanceDiff > params.investment && params.performanceFee != 0) {
        uint256 rewardAmount = params.balanceDiff - params.investment;
        uint256 fee = OperationsLib.getFeeAbsolute(rewardAmount, params.performanceFee);
        if (fee > 0) {
            address feeAddr = _getManager().feeAddress();
            emit FeeTaken(tokenIn, feeAddr, fee);
            IHolding(_recipient).transfer(tokenIn, feeAddr, fee);
        }
    }

    recipients[_recipient].totalShares -= _shares;
    recipients[_recipient].investedAmount = params.investment > recipients[_recipient].investedAmount
        ? 0
        : recipients[_recipient].investedAmount - params.investment;

    emit Withdraw({ asset: _asset, recipient: _recipient, shares: _shares, amount: params.balanceDiff });
    // Register `_recipient`'s withdrawal operation to stop generating jigsaw rewards.
    jigsawStaker.withdraw({ _user: _recipient, _amount: _shares });

    return (params.balanceDiff, params.investment);
}


This inconsistency could lead to the disruption of the strategies in case the tokens are not aligned correctly. Additionally it introduces unnecessary complexity and potential for future errors.

BVSS
Recommendation

Consider removing either tokenIn or weth and use a single reference consistently throughout the contract. Alternatively, ensure that tokenIn is always equal to weth. Add explicit documentation to clarify the token usage.

Remediation

SOLVED: The Jigsaw Protocol team solved this finding in commit 3b62613 by following the mentioned recommendation.

Remediation Hash
References

7.2 Incorrect Natspec documentation

//

Informational

Description

The Natspec documentation for the initialize() function is incorrect, as it refers to the initialize() function of the AaveStrategy contract.


Code Location

* - tokenOut: The address of the Aave receipt token (aToken).
BVSS
Recommendation

Update the Natspec documentation for the initialize() function in the DineroStrategy contract to accurately describe the function's tokenOut parameter.


Remediation

SOLVED: The Jigsaw Protocol team solved this finding in commit 8dc99e4 by following the mentioned recommendation.

Remediation Hash
References

7.3 Use of revert strings over custom errors

//

Informational

Description

Throughout the file in scope, there are several instances of use of revert strings over custom errors.


In Solidity development, replacing hard-coded revert message strings with the Error() syntax is an optimization strategy that can significantly reduce gas costs. Hard-coded strings, stored on the blockchain, increase the size and cost of deploying and executing contracts.


The Error() syntax allows for the definition of reusable, parameterized custom errors, leading to a more efficient use of storage and reduced gas consumption. This approach not only optimizes gas usage during deployment and interaction with the contract but also enhances code maintainability and readability by providing clearer, context-specific error information.

BVSS
Recommendation

Consider replacing all revert strings with custom errors. For example:

error ConditionNotMet();

if (!condition) revert ConditionNotMet();

For more reference, see here.

Remediation

ACKNOWLEDGED: The Jigsaw Protocol team made a business decision to acknowledge this finding and not alter the contracts.

References

8. Automated Testing

Static Analysis Report

Description

Halborn used automated testing techniques to enhance the coverage of certain areas of the smart contracts in scope. Among the tools used was Slither, a Solidity static analysis framework. After Halborn verified the smart contracts in the repository and was able to compile them correctly into their abis and binary format, Slither was run against the contracts. This tool can statically verify mathematical relationships between Solidity variables to detect invalid or inconsistent usage of the contracts' APIs across the entire code-base.

The security team assessed all findings identified by the Slither software, however, findings with related to external dependencies are not included in the below results for the sake of report readability.

Output

The findings obtained as a result of the Slither scan were reviewed, and the majority were not included in the report because they were determined as false positives.

Slither results

Halborn strongly recommends conducting a follow-up assessment of the project either within six months or immediately following any material changes to the codebase, whichever comes first. This approach is crucial for maintaining the project’s integrity and addressing potential vulnerabilities introduced by code modifications.

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