Full Report
Everyone has their own auditing methodology. Read the docs, don't read the docs, start with code, end with ... At the end of the day, the goal is to find all of the bugs. Most importantly for payouts in contests, are the unique findings. This author gives us some insight into some of their recent success. According to the author, projects with good tests have made them afraid to go hunt for bugs. They thought that if the code was really well tested then no bugs would exist in it. So, they decided to not look at the existing tests written by devs anymore. Now, they wrote all of their own tests from from scratch. They do this by getting a basic setup with a happy path. To them, the debugging is the most important part. They learn about the proper states of the project, right/wrong inputs and much more about the codebase. With a simple happy path going, they start writing their own tests to check for edge cases in the system. The blind spots of one person are going to be different than you, now that you're writing the tests. In a week long audit, they will spend the first 2-3 days writing tests and the rest of the time on code review. I find this methodology to be pretty interesting but frustrating. I personally read the docs to try to understand the purpose and flow of the project first. By doing this, you're essentially reverse engineering a protocol to write tests, which feels wasteful to me. The nice thing is that the uniqueness is what makes this work. If everyone did this then it wouldn't be nearly as effective. In the bug bounty space, niche tactics and weird vulnerabilities are the most important thing. Recently, they had 6 highs, including 2 solos at a Good Entry Code4rena contest. Thanks for the knowledge!
Analysis Summary
# Best Practices: Independent Security Auditing through Reverse-Engineered Testing
## Overview
These practices address the psychological bias and "blind spot" overlaps that occur when auditors rely on existing developer documentation and test suites. By adopting a "Clean Room" testing approach, auditors can uncover unique vulnerabilities and high-severity bugs that developers—and other auditors—consistently overlook.
## Key Recommendations
### Immediate Actions
1. **Ignore Pre-existing Test Suites:** Consciously avoid reviewing the project’s internal tests early in the audit to prevent "confirmation bias" (the belief that "well-tested" code is secure).
2. **Establish a Zero-Knowledge "Happy Path":** Immediately attempt to write and execute a basic setup that achieves one core function of the protocol (e.g., a simple deposit or swap).
3. **Identify Entry Points:** Map all public and external functions associated with a single piece of functionality before looking at implementation details.
### Short-term Improvements (1-3 months)
1. **Adopt a 40/60 Audit Split:** Allocate the first 2–3 days of a week-long audit exclusively to writing custom tests and debugging setup failures. Dedicate the remaining time to line-by-line manual code review.
2. **Build a Personal PoC Library:** Save successful "Happy Path" templates for common protocols (DeFi, NFTs, etc.) to accelerate future setup phases.
3. **Debug as Discovery:** Treat every test failure not as a nuisance, but as a critical learning event regarding the protocol’s required state and input expectations.
### Long-term Strategy (3+ months)
1. **Tool Customization:** Develop and refine your own testing wrappers or add-ons (e.g., specific Foundry scripts or Hardhat helpers) to handle edge cases like mainnet forks or complex fuzzing.
2. **Target Niche Vulnerabilities:** Use the unique perspective gained from manual test creation to look for "weird" vulnerabilities that standard automated tools and developer-written tests cannot detect.
## Implementation Guidance
### For Independent Auditors / Bug Hunters
- Use manual test creation as your primary method of "reverse engineering" the code logic.
- Do not seek shortcuts; the struggle to make a test pass is where the deepest understanding of the protocol is built.
### For Security Teams (Medium-sized)
- Implement "Red Team" rotations where one member is forbidden from reading the existing test suite and must attempt to break the system using only their own built tests.
- Compare the "blind spots" of the implementation team against the findings of the external perspective.
### For Large Enterprises / Audit Firms
- Standardize a "Proof of Concept (PoC) First" reporting culture. Ensure that 90% of the PoC infrastructure is built during the initial 2-3 day "Ramping Up" phase.
- Use diverse testing frameworks (Foundry, Certora, Echidna) to ensure tool-specific limitations don't create new blind spots.
## Configuration Examples
While the article focuses on methodology, the suggested technical workflow is:
1. **Setup Environment:** `forge init` or equivalent.
2. **State Initialization:** Manually define the `setUp()` function to include specific token balances, approvals, and contract deployments.
3. **Path Execution:**
solidity
function test_MyCustomHappyPath() public {
// 1. Manually set state
// 2. Call target function with "correct" inputs
// 3. Assert expected outcome
// 4. If fails: Debug state vs. expectation
}
## Compliance Alignment
- **NIST SP 800-115:** Aligns with technical security testing and examination guidelines, specifically the "Target Identification" and "Vulnerability Analysis" phases.
- **OWASP:** Supports "Negative Testing" and "Business Logic Testing" frameworks.
## Common Pitfalls to Avoid
- **Over-reliance on Docs:** Reading documentation too early can lead you to believe the code does what the author *intended*, rather than what it *actually* does.
- **Efficiency Paradox:** Avoiding the developer’s tests may feel "wasteful" or slow initially, but it is the primary way to find **unique/solo** findings that others miss.
- **Copy-Pasting Tests:** Avoid copying developer tests into your local environment; you will inherit their logic errors and blind spots.
## Resources
- **Code4rena:** Competitive auditing platform for practicing these tactics - [https://code4rena[.]com]
- **Immunefi:** Bug bounty platform focused on niche vulnerabilities - [https://immunefi[.]com]
- **Foundry:** Recommended Ethereum development and testing toolkit - [https://github[.]com/foundry-rs/foundry]