The rise of the code-based economy and the illusion of security
In the context of the decentralized economy expanding at an unprecedented rate, smart contracts have become the backbone for financial transactions worth billions of dollars without human intervention. However, the public and immutable nature of source code on the blockchain has created a risky environment where the slightest logic error can lead to irreversible financial loss. At Tan Phat Digital, we observe that smart contract audits appear as an essential solution to mitigate risks, but over-reliance on these reports has created a false sense of security among the investor and developer community. Understanding that auditing only provides a level of probabilistic security rather than absolute assurance is the first step to building a truly effective defense-in-depth strategy.
Smart contract auditing is essentially a technical review process performed by third-party security experts to detect programming errors, logic flaws, and architectural design flaws before the source code is deployed on the main network. However, a common misconception is to view the audit report as a "seal of approval" that the project is completely unhackable. In fact, an audit only reflects the state of the source code at a certain time and is based on a predetermined scope. The constant evolution of attack techniques, the emergence of artificial intelligence in finding vulnerabilities, and post-audit changes have caused the protective value of a single audit to decrease over time.
Technical and methodological limitations in traditional audits
Most audits today use a combination of automated tools and manual human review. Static analysis tools like Slither or Mythril are useful for scanning through thousands of lines of code to detect common errors like reentrancy or integer overflow, but they often produce a large number of false positives and can completely miss complex economic logic errors. Dynamic analysis and invariant testing through fuzzing can help uncover system edge states, but their effectiveness depends entirely on whether auditors can accurately define the security properties of the protocol.
The complexity of modern DeFi protocols, with interactions between multiple contracts and overlapping financial logic, is often beyond the ability of automated tools to cover. Sophisticated logic errors require profound intervention by experienced professionals. Below is a detailed analysis of current evaluation methods:
Static Analysis:
Coverage: Wide (Scans entire source code).
Ability to detect logic errors: Low (Mainly finds syntax errors and known vulnerability patterns) know).
Relative cost: Low.
Confidence level (2026): Basic level, just the beginning.
Manual Review:
Coverage: Focus on core logic core.
Ability to detect logic errors: High (Depends entirely on auditor's level and experience).
Relative cost: Medium to High.
Reliability level (2026): Very high but there is still risk due to human error.
Check Invariant Testing:
Coverage: According to predetermined scenarios.
Ability to detect logic errors: Average (Very effective for mathematical and financial margins).
Relative cost: Average.
Reliability level (2026): Becoming an increasing standard for DeFi projects.
Formal Verification:
Coverage: Narrow (Usually only applied to extremely important modules).
- smart contract security, but the cost and complexity of this method means it is usually only applied to fund management logic or cross-chain bridges. Even when validated, a mistake in writing the initial specification can invalidate the entire process.
Human Factors: Time Pressures, Budgets, and Lack of Accountability
One of the biggest risks in the audit process lies not in the source code but in operational factors. The pressure to launch products quickly often causes development teams to squeeze audit times, forcing auditors to work within unrealistic time frames. When time is limited, auditors are forced to prioritize core components and may ignore peripheral components or complex interaction scenarios with other protocols.
Budget issues also play a decisive role. According to Tan Phat Digital's analysis, many projects choose less reputable auditing units or require a narrow scope to save costs, leading to reports lacking in depth. On the contrary, hiring top companies may create a "brand tax" but still does not guarantee complete elimination of bugs if the project has a chaotic source code structure.
Lack of post-audit accountability is a big gap. Once the report is issued, responsibility for security rests entirely with the project team. If a vulnerability is exploited, auditing firms typically face no legal penalties. The information asymmetry between the technical team and investors causes the audit report to often be turned into a marketing tool instead of a technical document on risk management.
See more: What is a Smart Contract Audit?
Post-audit risks: Source code changes and implementation errors
An audited smart contract is only safe if the deployed source code version exactly matches the version version has been checked. Below are common types of risks after the audit process ends:
Source code changes (Delta):
Mechanism: The development team edits the code after audit (to optimize gas or fix minor errors) without performing a re-audit (re-audit).
Effects: Can invalidate the entire report audit because a small change can open a large vulnerability.
Mitigate: Require a re-audit delta for every change to the audited source code.
Initialization error:
Mechanism: Initialization functions (usually
initialize()in the upgradeable contracts) are not called atomically upon deployment.Impact: An attacker could take over the contract's admin rights immediately after deployment.
Mitigate: Use automated tools to check the deployment status on the main network.
Storage conflicts (Storage Collision):
EIP-1967 or use the Namespaced Storage structure.
Admin/Multisig Lock Risk:
Mechanism: A single individual takes control or the admin keys are not properly protected.
Impact: Risk of Rug Pull or Attack take control.
How to mitigate: Use a multi-signature wallet (Multisig) with a minimum 4/7 configuration and set up a time delay mechanism (Timelock).
Analyze economic logic errors and immutability violations
During 2024-2025, the blockchain industry sees a shift towards model-targeted attacks economic. These errors are extremely difficult to detect because the source code still executes syntactically, but the economic result is the opposite of the original intention. Below is a list of typical hacks due to logical and economic errors that Tan Phat Digital has compiled:
Yearn Finance (yETH) - December 2025:
Damage: 9.0 million USD.
Vulnerability: Error in the share calculation logic of stableswap pools old.
Lesson: Auditor needs to perform economic invariance tests between deposited assets and the amount of representative tokens issued.
Balancer - November 2025:
Loss: 120 million USD.
Vulnerability: Exploit rounding error in complex mathematical formulas.
Lesson: It is necessary to carefully examine mathematical margins and the risk from accumulating small errors over many transactions.
Garden Finance - October 2025:
Loss: More than 5.5 million USD.
Vulnerability: Attacks on multi-chain interaction model and bridge mechanism.
Lesson: Audit scope needs to expand to the entire interaction ecosystem instead of just focusing on a single chain.
Cork Protocol - Year 2025:
Vulnerability: Bias in the cumulative value of collateral (wstETH) model.
Lesson: All assumptions about the behavior of collateral must be validated from a third party.
See also: Is blockchain safe?
The new era of artificial intelligence: AI Agents and the threat to static auditing
The year 2025 marks a turning point when major language models (LLM) become AI agents capable of autonomously finding and exploiting vulnerabilities. Latest studies show that AI agents have achieved a success rate of more than 55% in exploiting new vulnerabilities. The emergence of these tools means that "zero-day" vulnerabilities can be discovered and exploited just minutes after the source code is deployed.
This requires a shift from a periodic audit model to continuous auditing and real-time monitoring. However, AI also brings opportunities: the cost of an "AI audit" is gradually decreasing, allowing hundreds of tests to be performed with low budgets, helping developers to stress-test contracts right in the development process (CI/CD).
Stakeholder risks: Oracles, Frontend and Off-chain infrastructure
Smart contract audits often only cover the source code on the chain, ignoring other important components. Tan Phat Digital recommends that projects pay attention to the following components:
Oracles system:
Main risks: Price manipulation or stale data.
Audit SC coverage: Low (usually only checks integrated logic, not source reliability). information).
Additional measures: Use reputable solutions such as Chainlink/Pyth and set up a data latency testing mechanism.
User interface (Frontend/UI):
Main risks: Domain hijacking (DNS Hijacking) or inserting malicious code into domains JavaScript library.
Audit SC coverage: No coverage at all.
Additional measures: Perform traditional Web2 security audits and use decentralized storage solutions.
Multisig/Admin Administration:
Main risk: Private key leak or human error in operation.
Audit SC coverage: Low.
Additional measures: Use cold wallets (hardware wallets) and geographical dispersion of signatories connection.
Off-chain infrastructure (Bots/Keepers):
Main risks: Liquidation bots fail or keepers stop working in volatile market conditions.
Audit SC coverage: No coverage.
Additional measures: Continuously monitor the bot's operational status and set up backup systems.
Investor psychology and warning signs (Red Flags)
For investors, the presentation in the audit report can be confusing. You need to clearly distinguish: "Resolved" (corrected) is completely different from "Acknowledged" (only recorded without editing). At Tan Phat Digital, we have compiled the top 5 warning signs:
Version mismatch report: The current source code has changed too much compared to the audited version.
Limited scope: The project only audits the token and not the core logic of the application (dApp).
Critical errors are not allowed. fix: High/Critical errors are still in "Acknowledged" status.
Auditor lacks credibility: Poor reporting, auditor has no reputation in the industry.
Lack of on-chain authentication: Advertising project is audited but does not publish verified source code on tools such as Etherscan.
Liability and new precedents in 2025
The rise in hacks has prompted regulators to reconsider liability. Recent lawsuits have established precedent that DAOs and their members can be held liable if smart contracts cause losses to investors. A default liability framework for Oracle (Default Oracle Liability) is also being discussed, whereby data providers are primarily responsible for errors arising from erroneous data.
However, legal enforcement of immutable contracts remains a major challenge. This ambiguity reinforces the importance of preventing risks right from the design stage instead of relying on compensation after the incident.
Towards a comprehensive risk management model: Defense in Depth
To truly protect assets, Tan Phat Digital recommends that Web3 projects switch to a Defense in Depth strategy including:
Culture Shift-Left Security: Integrate security tools right into programmers' daily workflow.
Multi-level auditing: Hire multiple independent units to get different critical perspectives.
Bug Bounty Program: Encourage the global white hat hacker community to continuously find bugs on platforms like Immunefi.
Real-time monitoring: Use early warning services to detect unusual on-chain behavior and trigger circuit breakers.
Insurance: Set up a reserve fund or buy insurance from entities like Nexus Mutual to compensate users when something goes wrong.
FAQs (FAQs)
Why can an audited smart contract still be hacked? Audits are often limited in time (usually 2-4 weeks) and scope, making it impossible for auditors to analyze every complex source code execution path. Additionally, new attack vectors are always emerging, and the source code may have been changed after the audit was completed without being retested.
What does the "Acknowledged" status in the audit report mean? This means that the development team was aware of the vulnerability but decided to leave it intact without fixing it. For investors, High or Critical errors in this state are a huge warning sign about the potential risk of the project.
What benefits does AI-driven auditing bring? AI helps detect vulnerabilities faster and token costs are about 70% lower than before. It allows developers to continuously stress-test their source code against attacking AI agents right in the development environment (CI/CD).
What is "SCONE-bench?" red? This method requires experts with extremely high mathematical skills to write specifications and prove the correctness of the source code. The cost usually increases from $20,000 to $50,000 compared to a regular audit and only applies to extremely important modules.
How did the 2025 Balancer hack happen? The attacker exploited a rounding error at the wei level in Composable Stable pools. By performing a continuous series of small-scale swap transactions, the attacker skewed the price calculation variable (invariant D) and depleted funds.
What is the risk from "Legacy Infrastructure"? When the project upgrades to a new version, the old contracts (V1, V2) still exist on the blockchain and may still hold user funds. If not disabled or defunded, they become easy targets for attacks because they are often not closely monitored.
What "Red Flags" should investors pay attention to when viewing audit reports? Be wary if the report is too old, the audit scope does not include core business logic, the auditor does not have a public reputation, or the project does not provide a link to the original report file.
How do we know the code on the chain matches the audited version? Investors need to compare the commit hash in the audit report with the source code version that has been authenticated on block explorers like Etherscan. If the source code has changed after the audit, the report is no longer warranted.
How is Bug Bounty different from traditional Audit? Audit is a testing process at a certain time by a small group of experts, while Bug Bounty is a program that continuously mobilizes thousands of global white hat hackers to find bugs after the project has been deployed.
How does the "Samuels v. Lido DAO" decision affect DAOs?The court established precedent that institutional investors participating in the governance of a DAO can be considered members of a "general partnership" and held jointly liable for violations by that DAO.
Why audits on Solana/Rust are expensive than Ethereum? Because the number of experts knowledgeable about Rust and Solana's specific architecture is still much smaller than Solidity, resulting in service fees that are often 20-30% higher.
How does "Circuit Breaker" help in the event of an attack? It allows the project to pause critical functions (such as withdrawals or exchanges) as soon as monitoring tools detect unusual behavior such as oracle price manipulation or large-scale capital withdrawals.
What is the "Initialization Front-Running" error? In upgradeable contracts, an attacker can monitor the deployment transaction and call the initialize function before the project can execute, thereby taking over administration and even destroying the contract.
What is Oracle's role in smart contract security? Oracle provides price and status data from outside the blockchain. If the contract logic is correct but the oracle is manipulated (e.g. via flash loan), the contract will execute erroneous commands leading to total capital loss.
Auditing is the beginning, not the end
Smart contract auditing is a powerful tool but never an invincible shield. Absolute security is unthinkable in the volatile open source environment. Stakeholders need to take a realistic view: audits help eliminate "known" bugs, but long-term safety depends on continuous monitoring and the integrity of the development team.
At Tan Phat Digital, we believe that security is not a static state, but a never-ending arms race. Understanding the limits of auditing will help us build systems that are not only "smart" but also truly resilient to the storms of decentralized finance.
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