Frontend Security Testing for AI-Generated Apps

Frontend Security Matters

AI-generated frontend code can expose sensitive data in client-side code, trust client-side validation, or create XSS vulnerabilities. Attackers can inspect and modify everything that ships to the browser, so test it directly.

Frontend Security Testing Checklist

Work through these 10 checks before deploying a client-facing application.

XSS vulnerability testing

Test all input fields and dynamic content rendering for reflected, stored, and DOM-based XSS vulnerabilities.

Client-side validation bypass

Test that security-critical validation is enforced on the backend and cannot be bypassed through client manipulation.

Sensitive data exposure

Review client-side code for hardcoded API keys, tokens, credentials, or sensitive business logic.

CORS policy testing

Verify CORS configuration to ensure only authorized origins can interact with your application.

Clickjacking protection

Test for X-Frame-Options or CSP frame-ancestors to prevent clickjacking attacks on sensitive pages.

Content Security Policy

Verify CSP headers are properly configured to prevent XSS and data injection attacks.

Local storage security

Review what data is stored in localStorage and sessionStorage for sensitive information exposure.

Third-party script review

Audit all third-party JavaScript libraries and CDN resources for supply chain security risks.

Authentication token handling

Verify JWT tokens or session identifiers are not exposed in URLs or insecure storage.

Postmessage security

Test postMessage handlers for origin validation and message injection vulnerabilities.

Common Frontend Vulnerabilities

DOM-Based XSS

JavaScript code dynamically creates HTML from user input without proper sanitization or encoding.

Exposed API Keys

API keys, tokens, or credentials hardcoded in client-side JavaScript or HTML source code.

Client-Side Trust

Application relies on client-side validation or authorization checks that a user can bypass.

Insecure Dependencies

Frontend libraries with known vulnerabilities or outdated packages.

Penetration Testing Guide

Complete penetration testing methodology

Code Security Scanning

Scan JavaScript code for vulnerabilities

Manual Security Testing

Manual testing techniques for client-side flaws

Common Security Flaws

Common vulnerabilities in AI-generated code

Scan Your Frontend Code

VibeEval scans the client-side code of your AI-generated app for exposed credentials, XSS, and insecure configurations.