Headline
GHSA-3fjj-p79j-c9hh: Fastify: Incorrect Content-Type parsing can lead to CSRF attack
Impact
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.
Patches
For 4.x users, please update to at least 4.10.2.
For 3.x users, please update to at least 3.29.4.
Workarounds
Implement Cross-Site Request Forgery protection using @fastify/csrf.
References
Check out the HackerOne report: https://hackerone.com/reports/1763832.
For more information
Impact
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.
Patches
For 4.x users, please update to at least 4.10.2.
For 3.x users, please update to at least 3.29.4.
Workarounds
Implement Cross-Site Request Forgery protection using @fastify/csrf.
References
Check out the HackerOne report: https://hackerone.com/reports/1763832.
For more information
Fastify security policy
References
- GHSA-3fjj-p79j-c9hh
- fastify/fastify@62dde76
Related news
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'.