CVE-2021-21322

fastify-http-proxy: crafted URL allows prefix scape of the proxied backend service

Published 2 Mar 2021Modified 17 Jun 2026CWE 20

In the Trivy database since at least 24 Oct 2026, 07:11 UTCWhen it arrived before that build is not recorded.

Severity by source

NVD9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

GHSA10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Red Hat10.0CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Trivy's own label is CRITICAL. Rated critical by NVD, Red Hat. Rated lower by GHSA (low).

Description

fastify-http-proxy is an npm package which is a fastify plugin for proxying your http requests to another server, with hooks. By crafting a specific URL, it is possible to escape the prefix of the proxied backend service. If the base url of the proxied server is `/pub/`, a user expect that accessing `/priv` on the target service would not be possible. In affected versions, it is possible. This is fixed in version 4.3.1.

Affected packages and fixed versions

Source	Package	Fixed in
npm::GitHub Security Advisory npm	fastify-http-proxy	4.3.1

References

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