AppTreasury Contract - Rezerve Money

Prepared by:

HALBORN

Last Updated 06/19/2025

Date of Engagement: June 12th, 2025 - June 13th, 2025

Summary

100% of all REPORTED Findings have been addressed

All findings

Critical

High

Medium

Low

Informational

1. Summary

Rezerve Money engaged Halborn to conduct a security assessment of their AppTreasury contract beginning on June 11th, 2025 and ending on June 12th, 2025. The security assessment was scoped to the smart contract provided in the GitHub repository. Commit hash and further details can be found in the Scope section of this report.

AppTreasury is a fork of OlympusDAO’s treasury with improved logic and monetary policies. The contact was upgraded to a recent solidity version and modified to be used using proxies. Credit and debit functionalities were added to allow for features such as PSM and staking rewards to later on come into the picture.

2. Assessment Summary

Halborn was provided 2 days for the engagement and assigned one full-time security engineer to review the security of the smart contract in scope. The engineer is 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 contract.
Ensure that smart contract functionality operates as intended.

In summary, Halborn identified some improvements to reduce the likelihood and impact of risks, which were partially addressed by the Rezerve Money team. The main ones were the following:

In the disable() function, consider removing the _toDisable address from the tokens array to be consistent with the enabledTokens mapping.
Make sure all inherited upgradable contracts are initialized.
Either add support to fee-on-transfer tokens or document that fee-on-transfer tokens are not supported.
Implement proper input validation in all functions.
Consider adding a constructor and calling the _disableinitializers() method inside.
Use the initializer modifier for the initial setup instead of reinitializer.

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.
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 ( $m_e$ )	METRIC VALUE	NUMERICAL 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

E

is calculated using the following formula:

$E = \prod m_e$

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 ( $m_I$ )	METRIC VALUE	NUMERICAL 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

I

is calculated using the following formula:

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

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 ( $C$ )	COEFFICIENT VALUE	NUMERICAL VALUE
Reversibility ( $r$ )	None (R:N) Partial (R:P) Full (R:F)	1 0.5 0.25
Scope ( $s$ )	Changed (S:C) Unchanged (S:U)	1.25 1

Severity Coefficient

C

is obtained by the following product:

$C = rs$

The Vulnerability Severity Score

S

is obtained by:

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

The score is rounded up to 1 decimal places.

Severity	Score Value Range
Critical	9 - 10
High	7 - 8.9
Medium	4.5 - 6.9
Low	2 - 4.4
Informational	0 - 1.9

5. SCOPE

REPOSITORY

(a) Repository: code

(b) Assessed Commit ID: dfc77dd

contracts/AppTreasury.sol

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

High

Medium

Low

Informational

Security analysis	Risk level	Remediation Date
Incomplete disable() Function	Low	Solved - 06/12/2025
Missing Initialization of Inherited Upgradable Contracts	Low	Solved - 06/15/2025
Potential Incompatibilities With fee-on-transfer Tokens	Low	Risk Accepted - 06/18/2025
Missing Input Validation	Low	Risk Accepted - 06/18/2025
Missing _disableInitializers() Call in the Constructor	Low	Risk Accepted - 06/18/2025
Misuse of reinitializer and Missing onlyInitializing on Subinitializer	Low	Risk Accepted - 06/18/2025
Inefficient Enabled Tokens Logic	Informational	Acknowledged - 06/18/2025
Unlocked Pragma Compiler	Informational	Solved - 06/14/2025
Use of Revert Strings Instead of Custom Errors	Informational	Acknowledged - 06/18/2025
Style Guide Optimizations	Informational	Acknowledged - 06/18/2025
Consider Using Named Mappings	Informational	Solved - 06/12/2025
Unsafe ERC20 Operation in Use	Informational	Solved - 06/15/2025
Cache Array Length Outside of Loop	Informational	Acknowledged - 06/18/2025
Inconsistent Error Messages	Informational	Acknowledged - 06/18/2025

7. Findings & Tech Details

7.1 Incomplete disable() Function

Low

Description

BVSS

AO:A/AC:L/AX:L/R:N/S:U/C:N/A:L/I:L/D:N/Y:N (3.1)

Recommendation

Remediation Comment

Remediation Hash

https://github.com/rezervemoney/code/commit/4c4d2c9d57875b28a7e9abe545bde88497216fe3

7.2 Missing Initialization of Inherited Upgradable Contracts

Low

Description

BVSS

AO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:L/D:N/Y:N (2.5)

Recommendation

Remediation Comment

Recommendation

Remediation Comment

Recommendation

Remediation Comment

Remediation Hash

https://github.com/rezervemoney/code/commit/4c4d2c9d57875b28a7e9abe545bde88497216fe3

7.12 Unsafe ERC20 Operation in Use

Informational

Description

BVSS

AO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:N/D:N/Y:N (0.0)

Recommendation

Remediation Comment

Remediation Hash

https://github.com/rezervemoney/code/commit/cb40ced1158c1c410582e446244ea64200fd25a2

7.13 Cache Array Length Outside of Loop

Informational

Description

BVSS

AO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:N/D:N/Y:N (0.0)

Recommendation

Remediation Comment

7.14 Inconsistent Error Messages

Informational

Description

BVSS

AO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:N/D:N/Y:N (0.0)

Recommendation

Remediation Comment

8. 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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AppTreasury Contract

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