Fix Security Misconfiguration in Qwik

Qwik's resumability model changes the attack surface. Security misconfigurations often stem from improper environment variable scoping and missing HTTP security headers in the SSR pipeline. In Qwik, anything prefixed with 'PUBLIC_' is serialized and shipped to the browser. If you're leaking secrets via the client-side manifest or running without a strict Content Security Policy (CSP), you're essentially handing over the keys to the kingdom.

The Vulnerable Pattern

// .env
PUBLIC_STRIPE_API_KEY=sk_live_51Mz...
// src/components/payment.tsx
import { component$ } from ‘@builder.io/qwik’;
export default component$(() => {
// VULNERABILITY: This secret is prefixed with PUBLIC_,
// meaning Qwik bundles it into the client-side JS/JSON state.
const apiKey = import.meta.env.PUBLIC_STRIPE_API_KEY;
return 
Payment Processor Active (ID: {apiKey})
;
});

The Secure Implementation

1. Environment Scoping: Qwik follows the Vite convention where only variables prefixed with 'PUBLIC_' are exposed to the client. Remove the 'PUBLIC_' prefix from any sensitive credentials to ensure they are only accessible via 'process.env' in server-side contexts. 2. Server-Side Execution: Use 'server$' or 'routeLoader$' to wrap any logic that requires secrets. This ensures the code is stripped from the client bundle. 3. Header Hardening: Qwik applications are often deployed as SSR apps. You must explicitly configure Security Headers (CSP, HSTS, X-Frame-Options) within your 'entry.ssr.tsx' or via your adapter's middleware (e.g., @builder.io/qwik-city/middleware/node) to prevent XSS and Clickjacking.

// .env
STRIPE_API_KEY=sk_live_51Mz...
// src/routes/index.tsx
import { component$ } from ‘@builder.io/qwik’;
import { server$ } from ‘@builder.io/qwik-city’;
// SECURE: Use server$ to ensure the logic and secrets never leave the server
const processPayment = server$(async (amount: number) => {
const secret = process.env.STRIPE_API_KEY;
// Perform sensitive logic here
return { success: true };
});
// entry.ssr.tsx
export default function (opts: RenderToStreamOptions) {
return renderToStream(, {
…opts,
// SECURE: Hardening headers at the SSR entry point
serverContext: {
‘Content-Security-Policy’: “default-src ‘self’; script-src ‘self’ ‘unsafe-inline’; object-src ‘none’;”,
‘X-Frame-Options’: ‘DENY’,
‘X-Content-Type-Options’: ‘nosniff’
}
});
}