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Earn V1 - Blueprint Finance

Prepared by:

Halborn Logo

HALBORN

Last Updated Unknown date

Date of Engagement: April 22nd, 2024 - July 19th, 2024

Summary

100% of all REPORTED Findings have been addressed

All findings

24

Critical

0

High

0

Medium

1

Low

4

Informational

19

Table of Contents

1. Introduction

Concrete engaged Halborn to conduct a security assessment on their smart contracts. This report includes four assessments carried out on the following schedules:

    • Money Printer assessment beginning on April 22nd, 2024 and ending on May 1st, 2024.

    • Money Printer Code Updates assessment beginning on May 20th, 2024 and ending on June 5th, 2024.

    • Earn diff assessment beginning on June 10th, 2024 and ending on June 17th, 2024.

    • Silo and Radiant Strategies assessment beginning on July 16th, 2024 and ending on July 19th, 2024.

2. Assessment Summary

The team at Halborn was provided one week for the engagement and assigned a full-time security engineer to verify the security of the smart contract. The security engineer is a blockchain and smart-contract security expert with advanced penetration testing, smart-contract hacking, and deep knowledge of multiple blockchain protocols.

The purpose of this assessment is to:

    • Ensure that smart contract functions operate as intended.

    • Identify potential security issues with the smart contracts.

In summary, Halborn identified some security risks that were mostly addressed/acknowledged by the Concrete team.

3. Test Approach and Methodology

Halborn performed a combination of manual 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 the code and can quickly identify items that do not follow the security best practices. The following phases and associated tools were used during the assessment:

    • Research into architecture and purpose.

    • Smart contract manual code review and walkthrough.

    • Graphing out functionality and contract logic/connectivity/functions (solgraph).

    • Manual assessment of use and safety for the critical Solidity variables and functions in scope to identify any arithmetic related vulnerability classes.

    • Manual testing by custom scripts.

    • Testnet deployment (Foundry).

3.1 Out-of-scope

    • External libraries and financial-related attacks.

    • Files located under src/examples/* folder.


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 (C:N)
Low (C:L)
Medium (C:M)
High (C:H)
Critical (C: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)+∑mI−max(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,EIC∗10)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

REPOSITORY
(a) Repository: sc_earn-v1
(b) Assessed Commit ID: 949c177
(c) Items in scope:
  • src/vault/ConcreteMultiStrategyVault.sol
  • src/swapper/Swapper.sol
  • src/swapper/OraclePlug.sol
↓ Expand ↓
Out-of-Scope: New features/implementations after the remediation commit IDs.

6. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

1

Low

4

Informational

19

Security analysisRisk levelRemediation Date
Logic issue on vault removalMediumSolved - 07/29/2024
Potential Denial of Service on prepare withdrawal functionLowRisk Accepted
Denial of service on _getStrategy functionLowSolved - 06/09/2024
ClaimRouter contract is using a mock interfaceLowRisk Accepted
Unchecked Return Values of ERC20 FunctionsLowSolved - 07/29/2024
Single step ownership transfer processInformationalAcknowledged
Owner can renounce OwnershipInformationalAcknowledged
A single compromised account can lock up the protocolInformationalAcknowledged
Potential denial of service on removeVault with block gas limitInformationalSolved - 06/09/2024
Checked increments in for loops increases gas consumptionInformationalSolved - 05/07/2024
Incomplete Error Handling in retireStrategyInformationalSolved - 07/29/2024
Missing checks for index out of boundsInformationalSolved - 05/07/2024
Use external instead of public methodsInformationalSolved - 05/07/2024
PUSH0 is not supported by all chainsInformationalAcknowledged
Missing zero address checksInformationalAcknowledged
Checked increments in for loops increases gas consumptionInformationalAcknowledged
Lack of validation on ProtectStrategyInformationalAcknowledged
Duplicated ImportsInformationalSolved - 07/30/2024
Events for Function CallsInformationalAcknowledged
Centralization risk: Lack of Access Control in requestFundsInformationalAcknowledged
Missing zero address checks on constructorInformationalSolved - 07/29/2024
Unrestricted Reward EnablingInformationalAcknowledged
Centralization risk: retireStrategyInformationalAcknowledged
No Events for claim functionInformationalAcknowledged

7. Findings & Tech Details

7.1 Logic issue on vault removal

//

Medium

Description
Proof of Concept
BVSS
Recommendation
Remediation Comment

7.2 Potential Denial of Service on prepare withdrawal function

//

Low

Description
BVSS
Recommendation
Remediation Comment

7.3 Denial of service on _getStrategy function

//

Low

Description
BVSS
Recommendation
Remediation Comment

7.4 ClaimRouter contract is using a mock interface

//

Low

Description
BVSS
Recommendation
Remediation Comment

7.5 Unchecked Return Values of ERC20 Functions

//

Low

Description
BVSS
Recommendation
Remediation Comment

7.6 Single step ownership transfer process

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.7 Owner can renounce Ownership

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.8 A single compromised account can lock up the protocol

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.9 Potential denial of service on removeVault with block gas limit

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.10 Checked increments in for loops increases gas consumption

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.11 Incomplete Error Handling in retireStrategy

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.12 Missing checks for index out of bounds

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.13 Use external instead of public methods

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.14 PUSH0 is not supported by all chains

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.15 Missing zero address checks

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.16 Checked increments in for loops increases gas consumption

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.17 Lack of validation on ProtectStrategy

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.18 Duplicated Imports

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.19 Events for Function Calls

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.20 Centralization risk: Lack of Access Control in requestFunds

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.21 Missing zero address checks on constructor

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.22 Unrestricted Reward Enabling

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.23 Centralization risk: retireStrategy

//

Informational

Description
BVSS
Recommendation
Remediation Comment

7.24 No Events for claim function

//

Informational

Description
BVSS
Recommendation
Remediation Comment

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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