Fastify Header Stripping Vulnerability Under Investigation
An early warning has been issued regarding a potential vulnerability in Fastify that may allow the stripping of proxy-added headers. This reportedly affects applications using @fastify/reply-from and @fastify/http-proxy plugins with custom header injection.
What happened
Fastify's connection header abuse is under investigation for enabling the stripping of proxy-added headers. This issue appears to impact applications that utilize the @fastify/reply-from and @fastify/http-proxy plugins with custom header injection for routing, access control, or security purposes.
To assess your exposure, review your application's use of these plugins and determine if custom header injection is employed. It is recommended to upgrade to the latest versions of @fastify/reply-from and @fastify/http-proxy to mitigate the risk of header stripping.
For more detailed information, consult the primary source at [GHSA-gwhp-pf74-vj37](https://github.com/advisories/GHSA-gwhp-pf74-vj37). The severity of this issue is currently classified as HIGH, and further details are expected as the investigation progresses.
How 0Day mitigates this
@fastify/reply-from is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.