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- [SCA] Metropolis World | TeamToken | Jan2025
Audit name:
[SCA] Metropolis World | TeamToken | Jan2025
Date:
Jan 7, 2025
Table of Content
Introduction
We express our gratitude to the Metropolis World team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.
Metropolis World, redefines social commerce, offering a gamified marketplace where digital collectibles unlock real-world assets and experiences, supported by pop-culture icons, powered by your digital identity.
Document | |
|---|---|
| Name | Smart Contract Code Review and Security Analysis Report for Metropolis World |
| Audited By | Seher Saylik |
| Approved By | Ataberk Yavuzer |
| Website | https://metropolisworld.io/→ |
| Changelog | 06/01/2025 - Preliminary Report |
| 07/01/2025 - Final Report | |
| Platform | Polygon Chain |
| Language | Solidity |
| Tags | Fungible Token; ERC20 |
| Methodology | https://hackenio.cc/sc_methodology→ |
Document
- Name
- Smart Contract Code Review and Security Analysis Report for Metropolis World
- Audited By
- Seher Saylik
- Approved By
- Ataberk Yavuzer
- Website
- https://metropolisworld.io/→
- Changelog
- 06/01/2025 - Preliminary Report
- 07/01/2025 - Final Report
- Platform
- Polygon Chain
- Language
- Solidity
- Tags
- Fungible Token; ERC20
- Methodology
- https://hackenio.cc/sc_methodology→
Review Scope | |
|---|---|
| Repository | https://polygonscan.com/token/0x2ab445c24c96db13383bb34678adae50c43b4baa#code→ |
| Commit | N/A |
Review Scope
- Commit
- N/A
Audit Summary
The system users should acknowledge all the risks summed up in the risks section of the report
Documentation quality
Functional requirements are partially missed.
Technical description is not provided.
Code quality
Several inefficient code usages were found.
The development environment is not configured.
Test coverage
Code coverage of the project is 0% (branch coverage) as no tests provided.
System Overview
Metropolis World is an ERC20 token with the following contracts:
BurnableTeamToken — a contract that implements an ERC20 token contract system, including a burnable extension that allows token holders to destroy their tokens or those they have an allowance for. It mints the total supply to the owner's address during the deployment.
It has the following attributes:
Name: to be determined during the deployment
Symbol: to be determined during the deployment
Decimals: to be determined during the deployment
Total supply: to be determined during the deployment
Potential Risks
Users can burn their tokens using the burn function or burn others’ tokens (within allowance limits) using burnFrom. If users accidentally burn tokens, the action is irreversible, leading to permanent loss.
The owner has no authority or centralized functionality other than the initial minting.
Findings
Code ― | Title | Status | Severity | |
|---|---|---|---|---|
| F-2025-8075 | Use of Floating Pragmas | accepted | Observation | |
| F-2025-8074 | Unused feeWallet Parameter | accepted | Observation | |
| F-2025-8073 | Validation Modifier Logic Flaw | accepted | Observation |
Appendix 1. Definitions
Severities
When auditing smart contracts, Hacken is using a risk-based approach that considers Likelihood, Impact, Exploitability and Complexity metrics to evaluate findings and score severities.
Reference on how risk scoring is done is available through the repository in our Github organization:
Severity | Description |
|---|---|
Critical | Critical vulnerabilities are usually straightforward to exploit and can lead to the loss of user funds or contract state manipulation. |
High | High vulnerabilities are usually harder to exploit, requiring specific conditions, or have a more limited scope, but can still lead to the loss of user funds or contract state manipulation. |
Medium | Medium vulnerabilities are usually limited to state manipulations and, in most cases, cannot lead to asset loss. Contradictions and requirements violations. Major deviations from best practices are also in this category. |
Low | Major deviations from best practices or major Gas inefficiency. These issues will not have a significant impact on code execution. |
Severity
- Critical
Description
- Critical vulnerabilities are usually straightforward to exploit and can lead to the loss of user funds or contract state manipulation.
Severity
- High
Description
- High vulnerabilities are usually harder to exploit, requiring specific conditions, or have a more limited scope, but can still lead to the loss of user funds or contract state manipulation.
Severity
- Medium
Description
- Medium vulnerabilities are usually limited to state manipulations and, in most cases, cannot lead to asset loss. Contradictions and requirements violations. Major deviations from best practices are also in this category.
Severity
- Low
Description
- Major deviations from best practices or major Gas inefficiency. These issues will not have a significant impact on code execution.
Potential Risks
The "Potential Risks" section identifies issues that are not direct security vulnerabilities but could still affect the project’s performance, reliability, or user trust. These risks arise from design choices, architectural decisions, or operational practices that, while not immediately exploitable, may lead to problems under certain conditions. Additionally, potential risks can impact the quality of the audit itself, as they may involve external factors or components beyond the scope of the audit, leading to incomplete assessments or oversight of key areas. This section aims to provide a broader perspective on factors that could affect the project's long-term security, functionality, and the comprehensiveness of the audit findings.
Appendix 2. Scope
The scope of the project includes the following smart contracts from the provided repository:
Scope Details | |
|---|---|
| Repository | https://polygonscan.com/token/0x2ab445c24c96db13383bb34678adae50c43b4baa#code→ |
| Commit | N/A |
| Whitepaper | N/A |
| Requirements | N/A |
| Technical Requirements | N/A |
Scope Details
- Commit
- N/A
- Whitepaper
- N/A
- Requirements
- N/A
- Technical Requirements
- N/A
Assets in Scope
Appendix 3. Additional Valuables
Additional Recommendations
The smart contracts in the scope of this audit could benefit from the introduction of automatic emergency actions for critical activities, such as unauthorized operations like ownership changes or proxy upgrades, as well as unexpected fund manipulations, including large withdrawals or minting events. Adding such mechanisms would enable the protocol to react automatically to unusual activity, ensuring that the contract remains secure and functions as intended.
To improve functionality, these emergency actions could be designed to trigger under specific conditions, such as:
Detecting changes to ownership or critical permissions.
Monitoring large or unexpected transactions and minting events.
Pausing operations when irregularities are identified.
These enhancements would provide an added layer of security, making the contract more robust and better equipped to handle unexpected situations while maintaining smooth operations.