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Orange A-1

Security Audit

May 23rd, 2024

Version 1.0.0

Presented by 0xMacro

Table of Contents

Introduction

This document includes the results of the security audit for Orange's smart contract code as found in the section titled ‘Source Code’. The security audit was performed by the Macro security team on May 16th, 2024.

The purpose of this audit is to review the source code of certain Orange Solidity contracts, and provide feedback on the design, architecture, and quality of the source code with an emphasis on validating the correctness and security of the software in its entirety.

Disclaimer: While Macro’s review is comprehensive and has surfaced some changes that should be made to the source code, this audit should not solely be relied upon for security, as no single audit is guaranteed to catch all possible bugs.

Overall Assessment

The following is an aggregation of issues found by the Macro Audit team:

Severity Count Acknowledged Won't Do Addressed
Medium 1 - - 1
Low 1 - - 1
Code Quality 5 - 1 4
Informational 2 - - -

Orange was quick to respond to these issues.

Specification

Our understanding of the specification was based on the following sources:

Source Code

The following source code was reviewed during the audit:

Specifically, we audited the following contract within this repository:

Contract SHA256
contracts/SaleDeposit.sol

d683d39641c7ae45992a55cbdbbece367a10a9541502d87f5c63706013d7fcf0

contracts/SaleDepositWhitelist.sol

469e581cbd62fec9f0c6de82838661ae3de97067793dad9febd749fff7532b27

Note: This document contains an audit solely of the Solidity contracts listed above. Specifically, the audit pertains only to the contracts themselves, and does not pertain to any other programs or scripts, including deployment scripts.

Issue Descriptions and Recommendations

Click on an issue to jump to it, or scroll down to see them all.

Security Level Reference

We quantify issues in three parts:

  1. The high/medium/low/spec-breaking impact of the issue:
    • How bad things can get (for a vulnerability)
    • The significance of an improvement (for a code quality issue)
    • The amount of gas saved (for a gas optimization)
  2. The high/medium/low likelihood of the issue:
    • How likely is the issue to occur (for a vulnerability)
  3. The overall critical/high/medium/low severity of the issue.

This third part – the severity level – is a summary of how much consideration the client should give to fixing the issue. We assign severity according to the table of guidelines below:

Severity Description
(C-x)
Critical

We recommend the client must fix the issue, no matter what, because not fixing would mean significant funds/assets WILL be lost.

(H-x)
High

We recommend the client must address the issue, no matter what, because not fixing would be very bad, or some funds/assets will be lost, or the code’s behavior is against the provided spec.

(M-x)
Medium

We recommend the client to seriously consider fixing the issue, as the implications of not fixing the issue are severe enough to impact the project significantly, albiet not in an existential manner.

(L-x)
Low

The risk is small, unlikely, or may not relevant to the project in a meaningful way.

Whether or not the project wants to develop a fix is up to the goals and needs of the project.

(Q-x)
Code Quality

The issue identified does not pose any obvious risk, but fixing could improve overall code quality, on-chain composability, developer ergonomics, or even certain aspects of protocol design.

(I-x)
Informational

Warnings and things to keep in mind when operating the protocol. No immediate action required.

(G-x)
Gas Optimizations

The presented optimization suggestion would save an amount of gas significant enough, in our opinion, to be worth the development cost of implementing it.

Issue Details

M-1

The Owner can renounce ownership, leading to inaccessible assets

Topic
Best practices
Status
Impact
High
Likelihood
Low

Both SaleDeposit and SaleDepositWhitelist contracts inherit from the Ownable OZ library. The Ownable library has the renounceOwnerhship() capability, which, if invoked by the owner intentionally or by mistake, will set address(0) as the current owner.

As a result, all functions protected by the modifier onlyOwner() will no longer be accessible. This also includes the withdraw() function, which is the only mechanism to access deposited assets.

Remediations to consider

  • To prevent losing access to assets, override the renounceOwnership() function and revert to prevent parent implementation from resetting the owner.
L-1

Withdraw may transfer assets to 0 address

Topic
Best practices
Status
Impact
High
Likelihood
Low

In SaleDeposit and SaleDepositWhitelist contracts, the withdraw() function implementation allows _recipient input address to be 0 address. In addition, natspec comments for these functions indicate that withdraw() ”could be used to transfer the token to the 0 address”.

However, if this happens, assets will be unretrievable and lost.

Remediations to consider

  • Add validation check to prevent sending assets to the _recipient with 0 address.
Q-1

SafeMath unnecessary in 0.8+ Solidity version

Topic
Best practices
Status
Quality Impact
Low

The SafeMath lib is used in SaleDeposit and SaleDepositWhitelist contracts. However, SafeMath is unnecessary as Solidity in versions 0.8+ has, by default, overflow and underflow checks.

Consider removing SafeMath from these two contracts and replacing instances of mul() operation calls with default * operation.

Q-2

Solidity pragma should be specific, not wide

Topic
Best practices
Status
Quality Impact
Low

Consider using a specific version of Solidity in your contracts instead of a wide version. For example, instead of pragma solidity ^0.8.0;, use pragma solidity 0.8.14;

  • Found in contracts/SaleDeposit.sol Line: 1

    pragma solidity ^0.8.13;
    
  • Found in contracts/SaleDepositWhitelist.sol Line: 1

    pragma solidity ^0.8.13;
    
Q-3

PUSH0 is not supported by all chains

Topic
Best practices
Status
Quality Impact
Low

Solc compiler version 0.8.20 switches the default target EVM version to Shanghai, which means that the generated bytecode will include PUSH0 opcodes. Be sure to select the appropriate EVM version in case you intend to deploy on a chain other than mainnet like L2 chains or alternative L1s that may not support PUSH0, otherwise deployment of your contracts will fail.

  • Found in contracts/SaleDeposit.sol Line: 1

    pragma solidity ^0.8.13;
    
  • Found in contracts/SaleDepositWhitelist.sol Line: 1

    pragma solidity ^0.8.13;
    
Q-4

Use Solidity custom errors

Topic
Best practices
Status
Wont Do
Quality Impact
Low

Since version 0.8.4, custom errors represent a more convenient and gas-efficient way to explain to users why an operation failed. Consider replacing current require expressions with string errors with custom errors.

Response by Orange

We are still comfortable to just use the require approach here, since we experienced some decoding issues in explorers when we tried custom error approach.

Q-5

Update OpenZeppelin dependency to the latest version

Topic
Best practices
Status
Quality Impact
Low

Currently, the project relies on OpenZeppelin dependency with version "^4.3.1". Many versions, including the one mentioned, have been affected by published security advisories in the past.

// in package.json
"@openzeppelin/contracts": "^4.3.1"

Consider updating the open Zeppelin library dependency to the latest version without known security advisories - currently, that is v4.9.6.

I-1

Centralization risk

Topic
Trust model
Impact
Informational

Both SaleDeposit and SaleDepositWhitelist contracts are designed to collect user asset deposits and enable the contract owner to withdraw them. The contract owner must be trusted to perform the expected actions upon withdrawing users’ deposits.

In addition, the owner may update the allowlist at any time in the case of the SaleDepositWhitelist contract.

Response by Orange

This is part of our business requirements.

I-2

There are limits per transaction but not per user

Topic
Spec
Impact
Informational

Within implemented contracts, limits restrict the number of reserved slots that users may obtain in a single call. However, these limits may be circumvented with multiple calls.

Response by Orange

This is part of our business requirements.

Disclaimer

Macro makes no warranties, either express, implied, statutory, or otherwise, with respect to the services or deliverables provided in this report, and Macro specifically disclaims all implied warranties of merchantability, fitness for a particular purpose, noninfringement and those arising from a course of dealing, usage or trade with respect thereto, and all such warranties are hereby excluded to the fullest extent permitted by law.

Macro will not be liable for any lost profits, business, contracts, revenue, goodwill, production, anticipated savings, loss of data, or costs of procurement of substitute goods or services or for any claim or demand by any other party. In no event will Macro be liable for consequential, incidental, special, indirect, or exemplary damages arising out of this agreement or any work statement, however caused and (to the fullest extent permitted by law) under any theory of liability (including negligence), even if Macro has been advised of the possibility of such damages.

The scope of this report and review is limited to a review of only the code presented by the Orange team and only the source code Macro notes as being within the scope of Macro’s review within this report. This report does not include an audit of the deployment scripts used to deploy the Solidity contracts in the repository corresponding to this audit. Specifically, for the avoidance of doubt, this report does not constitute investment advice, is not intended to be relied upon as investment advice, is not an endorsement of this project or team, and it is not a guarantee as to the absolute security of the project. In this report you may through hypertext or other computer links, gain access to websites operated by persons other than Macro. Such hyperlinks are provided for your reference and convenience only, and are the exclusive responsibility of such websites’ owners. You agree that Macro is not responsible for the content or operation of such websites, and that Macro shall have no liability to your or any other person or entity for the use of third party websites. Macro assumes no responsibility for the use of third party software and shall have no liability whatsoever to any person or entity for the accuracy or completeness of any outcome generated by such software.