Introduction
We express our gratitude to the Humans team for the collaborative engagement that enabled the execution of this Smart Contract Security Assessment.
Humans is an AI platform that integrates deeply with a company/community/country’s human expertise through rich dialogues, crafting AI agents tailored to both explicit and implicit needs.
| title | content |
|---|---|
| Platform | Ethereum |
| Language | Solidity |
| Tags | ERC-20 |
| Timeline | 26/11/2021 – 06/12/2021 |
| Methodology | https://hackenio.cc/sc_methodology→ |
Review Scope | |
|---|---|
| Repository | https://github.com/0x4139/humans-smart-contract→ |
| Commit | 7fee64d49359b22f4dbb848b0ab05e412f422b1c |
Review Scope
- Commit
- 7fee64d49359b22f4dbb848b0ab05e412f422b1c
Audit Summary
The system users should acknowledge all the risks summed up in the risks section of the report
Document Information
This report may contain confidential information about IT systems and the intellectual property of the Customer, as well as information about potential vulnerabilities and methods of their exploitation.
The report can be disclosed publicly after prior consent by another Party. Any subsequent publication of this report shall be without mandatory consent.
Document | |
|---|---|
| Name | Smart Contract Code Review and Security Analysis Report for Humans |
| Audited By | Hacken |
| Approved By | Hacken |
| Website | https://humans.ai→ |
| Changelog | 02/12/2021 – Initial audit |
| 03/12/2021 – Second audit | |
| 06/12/2021 – Final review |
Document
- Name
- Smart Contract Code Review and Security Analysis Report for Humans
- Audited By
- Hacken
- Approved By
- Hacken
- Website
- https://humans.ai→
- Changelog
- 02/12/2021 – Initial audit
- 03/12/2021 – Second audit
- 06/12/2021 – Final review
System Overview
Conclusion
Smart contracts within the scope were manually reviewed and analyzed with static analysis tools.
The audit report contains all found security vulnerabilities and other issues in the reviewed code.
As a result of the audit, security engineers found 3 low severity issues.
After the second review security engineers found 1 medium severity issue and also wallets list was changed.
After the third review security engineers found all issues were addressed.
Executive Summary
According to the assessment, the Customer's smart contracts are well-secured.
Our team performed an analysis of code functionality, manual audit, and automated checks with Mythril and Slither. All issues found during automated analysis were manually reviewed, and important vulnerabilities are presented in the Audit overview section. All found issues can be found in the Audit overview section.
As a result of the audit, security engineers found 3 low severity issues.
After the second review security engineers found 1 medium severity issue and also wallets list was changed.
After the third review security engineers found all issues were addressed.
Findings
Code ― | Title | Status | Severity | |
|---|---|---|---|---|
| F-2021-0103 | Inconsistency in the tokenomics | fixed | Medium | |
| F-2021-0106 | Too many digits | fixed | Low | |
| F-2021-0105 | Boolean equality | fixed | Low | |
| F-2021-0104 | A public function that could be declared external | fixed | Low |
Appendix 1. Severity Definitions
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, do not affect security score but can affect code quality score. |
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, do not affect security score but can affect code quality score.
Appendix 2. Scope
The scope of the project includes the following smart contracts from the provided repository:
Scope Details | |
|---|---|
| Repository | https://github.com/0x4139/humans-smart-contract→ |
| Commit | 7fee64d49359b22f4dbb848b0ab05e412f422b1c |
| Whitepaper | Provided→ |
| Requirements | Provided→ |
| Technical Requirements | Provided→ |