{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.3.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "33dba25c32af41beafc3cbb7139e2708bfda26db"
            },
            {
              "fixed": "02d9b43c770aa16bc44470edecfaeb7c17985016"
            }
          ],
          "repo": "https://github.com/fastify/fastify-http-proxy",
          "type": "GIT"
        }
      ]
    }
  ],
  "details": "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.",
  "id": "CVE-2021-21322",
  "modified": "2026-03-13T21:54:25.147117029Z",
  "published": "2021-03-02T04:15:12.597Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-c4qr-gmr9-v23w"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.npmjs.com/package/fastify-http-proxy"
    },
    {
      "type": "FIX",
      "url": "https://github.com/fastify/fastify-http-proxy/commit/02d9b43c770aa16bc44470edecfaeb7c17985016"
    }
  ],
  "related": [
    "GHSA-c4qr-gmr9-v23w"
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}