Fix security headers are not configured in Fastify

The application does not set the baseline security response headers. Without them a browser will not enforce HTTPS, will guess content types, and will allow the page to be framed. Headers set by a CDN or ingress are invisible to static analysis, so this rule reports lower confidence when it finds no header configuration at all.

medium likely Fastify CWE-693 / OWASP A05:2021

The vulnerable pattern in Fastify

MEDIUM possible Security headers are not configured A05:2021 src/server.ts:12:7 10 │ 11 │ const app = Fastify({ logger: true }) 12 │ await app.register(cookie) │ ~~~~~~~~~~~~~~~~~~~~ no security headers configured here 13 │ 14 │ const db = await mysql.createConnection(process.env.DATABASE_URL ?? '')

This finding comes from the Fastify fixture in the owlwarden test suite. Without these headers the browser enforces nothing: strict-transport-security forces HTTPS for future requests; content-security-policy limits which scripts and origins the page may load; x-content-type-options stops browsers guessing a response's content type; x-frame-options blocks clickjacking via framing; referrer-policy stops URLs leaking to third parties.

The corrected handler

Register @fastify/helmet before your routes.

import helmet from '@fastify/helmet'

await app.register(helmet)

If you are not using Fastify

Set these response headers at the edge or in the app: strict-transport-security, content-security-policy, x-content-type-options, x-frame-options, referrer-policy.

Check your own repository

npx owlwarden scan
npx owlwarden explain security-headers-missing

Runs on your machine. No account, no telemetry, no network unless you ask. In CI, SARIF uploads to code scanning and the exit code is the gate.

Other Fastify checks

Rules with a tested Fastify example.

security-headers-missing for every framework / All rules / owlwarden