@fastify/reply-from JSON Content-Type parsing confusion

Impact

The main repo of fastify use fast-content-type-parse to parse request Content-Type, which will trim after split.

The fastify-reply-from have not use this repo to unify the parse of Content-Type, which won’t trim.

As a result, a reverse proxy server built with @fastify/reply-from could misinterpret the incoming body by passing an header ContentType: application/json ; charset=utf-8. This can lead to bypass of security checks.

Patches

@fastify/reply-from v9.6.0 include the fix.

Workarounds

There are no known workarounds.

References

Hackerone Report: https://hackerone.com/reports/2295770.