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Decent Contracts - Decent Labs

Prepared by:

Halborn Logo

HALBORN

Last Updated 09/16/2025

Date of Engagement: August 18th, 2025 - August 26th, 2025

Summary

100% of all REPORTED Findings have been addressed

All findings

6

Critical

0

High

0

Medium

0

Low

1

Informational

5

Table of Contents

1. Introduction

Decent Labs engaged Halborn to perform a security assessment of their smart contracts from August 18th, 2025, to August 26th, 2025. The assessment scope was limited to the smart contracts provided to Halborn. Commit hashes and additional details are available in the Scope section of this report.


The Decent Labs codebase in scope consists of smart contracts implementing a modular token sale system with EIP-712-based buyer verification, a non-transferable ERC20 staking and rewards mechanism, and a system deployer contract for proxy deployments.

2. Assessment Summary

Halborn was allocated 7 days for this engagement and assigned 1 full-time security engineer to conduct a comprehensive review of the smart contracts within scope. The engineer is an expert in blockchain and smart contract security, with advanced skills in penetration testing and smart contract exploitation, as well as extensive knowledge of multiple blockchain protocols.


The objectives of this assessment were to:

    • Identify potential security vulnerabilities within the smart contracts.

    • Verify that the smart contract functionality operates as intended.


In summary, Halborn identified areas for improvement to reduce the likelihood and impact of potential risks, which were partially addressed by the Decent Labs team:

    • Update the _distributeRewards() function to increment rewardsDistributed only by the amount actually allocated to stakers, not the full amountToDistribute.

    • Add a check in the initialize() function to ensure that protocolFeeReceiver is not the zero address.

    • Add a validation check in _validateHedgeyParams to ensure that cliff_ is greater than or equal to start_.


3. Test Approach and Methodology

Halborn conducted a combination of manual code review and automated security testing to balance efficiency, timeliness, practicality, and accuracy within the scope of this assessment. While manual testing is crucial for identifying flaws in logic, processes, and implementation, automated testing enhances coverage of smart contracts and quickly detects deviations from established security best practices.

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

    • Research into the platform's architecture, purpose and use.

    • Manual code review and walkthrough of smart contracts to identify any logical issues.

    • Comprehensive assessment of the safety and usage of critical Solidity variables and functions within scope that could lead to arithmetic-related vulnerabilities.

    • Local testing using custom scripts (Foundry).

    • Fork testing against main networks (Foundry).

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


4. Caveats

After the conclusion of this assessment, the Decent Labs team introduced a minor update to the VotesERC20Staked contract in commit d7137b1 in order to support compatibility with both version 0 and version 1 deployments. Specifically, a clockModeTimestamp boolean variable was added to storage and initialization, with corresponding updates to the CLOCK_MODE() and clock() functions. This change allows the contract to operate using either block timestamps or block numbers as the underlying clock mechanism.


Although this modification was introduced after the commit reviewed during the assessment and therefore falls outside the official scope of this engagement, Halborn reviewed the update at a high level. Based on this review, it was concluded that the change is limited in scope and does not appear to introduce any new security risks.

5. 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.

5.1 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

5.2 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}

5.3 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

6. SCOPE

REPOSITORY
(a) Repository: decent-contracts
(b) Assessed Commit ID: 153d06a
(c) Items in scope:
  • contracts/deployables/erc20/VotesERC20StakedV1.sol
  • contracts/deployables/token-sale/TokenSaleV1.sol
  • contracts/services/verifier/VerifierV1.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.

7. Assessment Summary & Findings Overview

Critical

0

High

0

Medium

0

Low

1

Informational

5

Security analysisRisk levelRemediation Date
Suboptimal reward accounting can permanently lock dust amounts in contractLowRisk Accepted - 09/02/2025
Missing validation for protocolFeeReceiver may result in lost fundsInformationalAcknowledged - 09/02/2025
Vesting schedule allows cliff to be set before vesting startInformationalSolved - 09/02/2025
Staked token can be added as a reward tokenInformationalSolved - 09/02/2025
Missing input validationInformationalAcknowledged - 09/02/2025
Floating pragmaInformationalAcknowledged - 09/02/2025

8. Findings & Tech Details

8.1 Suboptimal reward accounting can permanently lock dust amounts in contract

//

Low

Description
BVSS
Recommendation
Remediation Comment

8.2 Missing validation for protocolFeeReceiver may result in lost funds

//

Informational

Description
BVSS
Recommendation
Remediation Comment

8.3 Vesting schedule allows cliff to be set before vesting start

//

Informational

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash
https://github.com/decentdao/decent-contracts/commit/3b82717d163cc0752ad782095c69738fb79aac32

8.4 Staked token can be added as a reward token

//

Informational

Description
BVSS
Recommendation
Remediation Comment
Remediation Hash
https://github.com/decentdao/decent-contracts/commit/296efe6e27a28c6d19b759421cfdf349af87455f

8.5 Missing input validation

//

Informational

Description
BVSS
Recommendation
Remediation Comment

8.6 Floating pragma

//

Informational

Description
BVSS
Recommendation
Remediation Comment

9. Automated Testing

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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Decent Contracts

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