Bypassing CORS Protection via Incorrect Content-Type in Fastify

CVE-2022-41919 · HIGH Severity

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Fastify is a web framework with minimal overhead and plugin architecture. The attacker can use the incorrect `Content-Type` to bypass the `Pre-Flight` checking of `fetch`. `fetch()` requests with Content-Type’s essence as "application/x-www-form-urlencoded", "multipart/form-data", or "text/plain", could potentially be used to invoke routes that only accepts `application/json` content type, thus bypassing any CORS protection, and therefore they could lead to a Cross-Site Request Forgery attack. This issue has been patched in version 4.10.2 and 3.29.4. As a workaround, implement Cross-Site Request Forgery protection using `@fastify/csrf'.

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