TypeScriptAuditPentestingWeb3 Security
Why TypeScript Audits Are Critical for Web3 Security & DeFi dApp Protection
September 10, 2025•
Fernando Velázquez
When people discuss Web3 security, the focus is usually on smart contract audits. In reality, securing only the on-chain code isn't enough. Modern decentralized applications (dApps), especially in DeFi, rely heavily on TypeScript for both frontend and backend workflows. Overlooking this layer can leave critical vulnerabilities wide open.
The Overlooked Attack Surface: TypeScript Security Risks in DeFi dApps
At Zealynx Security, we regularly see that vulnerabilities in dApps are not limited to smart contracts. TypeScript code forms a significant part of the attack surface for DeFi projects. Real-world incidents have shown that weaknesses here can result in unauthorized blockchain transactions, bypassed access controls, and manipulation of off-chain data feeding directly into smart contracts. In many cases, these issues are even easier for attackers to exploit than flaws in the contracts themselves. That’s why robust TypeScript audits are essential for any serious DeFi project.
Why TypeScript Audits Matter for Blockchain Security
TypeScript is much more than just "glue code" between users and the blockchain. It acts as the orchestration layer for your dApp, handling wallet integrations, user authentication, transaction approval and signing workflows, and managing data from oracles, event logs, and off-chain APIs. It’s also responsible for validating input before blockchain interaction and integrating with third-party DeFi tools like price feeds, NFT metadata, and aggregators. A single insecure fetch, unchecked URI, or poorly validated input can expose your protocol to multi-vector attacks—even if your smart contracts are bulletproof.
Common TypeScript Vulnerabilities in dApps
Our TypeScript audits frequently uncover issues such as direct contract calls that don’t verify the signer's identity or application state, unvalidated user inputs that enable malicious behavior, and client-side bypasses for KYC, whitelisting, or access controls. We also come across hardcoded secrets in frontend code, which can leak API keys or sensitive endpoints.
Classic Web2 security issues are still highly relevant to Web3. We routinely find:
- Cross-Site Scripting (XSS): Attackers injecting scripts to modify transaction data before signing
- Cross-Site Request Forgery (CSRF): Exploits targeting APIs that trigger blockchain actions or wallet integrations
- Insecure Direct Object References (IDOR): Unprotected APIs managing user assets or NFT metadata
- Open Redirects: Used for phishing or wallet-draining in authentication or referral flows
- Improper CORS Configurations: Allowing untrusted origins to access sensitive APIs
Zealynx's TypeScript Audit Methodology
To deliver comprehensive coverage, we combine both static and dynamic analysis. Our process begins with a manual review of critical code paths, including wallet connections, signing logic, and data handling. We focus on identifying insecure functions, unsafe type casting, dependency risks, and tracing frontend-to-contract interactions for potential abuse paths.
Dynamic analysis follows, where we simulate real-world attacks by attempting to bypass controls, exploit APIs, and manipulate user inputs. We observe how the dApp behaves when faced with inconsistent states or unexpected API responses. This approach helps us detect validation gaps and unsafe handling of live data, enabling us to catch both design flaws and runtime vulnerabilities. The result is actionable, high-impact findings that help our clients secure their applications.
Industry Standards for TypeScript & Web3 Security
All Zealynx audits adhere to industry best practices. We follow the OWASP Top 10 for web, API, and LLM applications, as well as the OWASP Mobile and Client-Side Security Testing Guides and the OWASP API Security Top 10. These frameworks ensure our findings are practical, actionable, and benchmarked against the highest standards in blockchain and Web3 security.
Real-World Example: Stopping Critical Frontend Exploits
Our approach delivers real results. In a recent audit with Pashov Audit Group for Initia Protocol, we uncovered a high-severity XSS vulnerability in the TypeScript frontend. The issue involved unvalidated user input being rendered directly, which exposed users to script injection and data theft. By identifying and fixing this before launch, we helped the client secure user flows and protect sensitive data. This is a perfect example of why TypeScript audits are essential for DeFi projects.
Takeaway: Even well-built dApps can hide frontend risks. A thorough TypeScript audit closes these gaps before attackers can exploit them.
Why Zealynx Is the Go-To for TypeScript & DeFi Security Audits
Attackers don’t care if the weak link is on-chain or off-chain—they will exploit whatever is easiest. If your frontend bridges users and contracts, it is part of your security perimeter. Neglecting TypeScript security means transaction logic can be altered, user flows hijacked, and off-chain dependencies poisoned, even in otherwise "secure" contracts.
A Zealynx TypeScript audit closes these gaps and builds full-stack trust for your users and investors.
What to Expect from a Zealynx TypeScript Audit
When you choose Zealynx, you get:
- Fast turnaround: Actionable findings delivered in days, not weeks
- Clear, prioritized reporting: No jargon—just practical steps to secure your dApp
- End-to-end coverage: From wallet integrations to backend APIs
- Ongoing support: Help during remediation and after deployment
Ready to Secure Your DeFi dApp End-to-End?
If you’re scaling your DeFi project or preparing for a major launch, a TypeScript audit is the missing piece for complete Web3 security.
Request a quote or schedule a free scoping call — no obligation, just practical advice from blockchain security experts.
