Security advisory

{
  "id": "9dbb0788e126a59b5dc571b06ea65342c38b005177b30e65c9a26e98e4d03947",
  "url": "https://osv.dev/vulnerability/CVE-2021-21322",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-21322",
    "summary": "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.",
    "evidence": "osv:CVE-2021-21322",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2021-21322",
      "aliases": [
        "CVE-2021-21322",
        "GHSA-c4qr-gmr9-v23w"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/fastify/fastify-http-proxy",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "33dba25c32af41beafc3cbb7139e2708bfda26db"
                },
                {
                  "fixed": "02d9b43c770aa16bc44470edecfaeb7c17985016"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:fastify-http-proxy_project:fastify-http-proxy:*:*:*:*:*:node.js:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "4.3.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "02d9b43c770aa16bc44470edecfaeb7c17985016"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.3.0",
            "v4.2.0",
            "v4.1.0",
            "v4.0.4",
            "v4.0.3",
            "v4.0.2",
            "v4.0.1",
            "v4.0.0",
            "v3.2.0",
            "v3.1.0",
            "v3.0.0",
            "v2.3.0",
            "v2.2.0",
            "v2.1.0",
            "v2.0.3",
            "v2.0.2",
            "v2.0.1",
            "v1.0.0",
            "v0.8.0",
            "v0.7.0",
            "v0.6.0",
            "v0.4.3",
            "v0.4.2",
            "v0.4.1",
            "v0.4.0",
            "v0.3.0",
            "v0.2.1",
            "v0.2.0",
            "v0.1.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-21322.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:28.998827735Z",
      "provider": "osv",
      "references": [
        "https://github.com/fastify/fastify-http-proxy/security/advisories/GHSA-c4qr-gmr9-v23w",
        "https://www.npmjs.com/package/fastify-http-proxy",
        "https://github.com/fastify/fastify-http-proxy/commit/02d9b43c770aa16bc44470edecfaeb7c17985016"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-21322",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385439,
  "published_at": "2021-03-02T04:15:12.597+00:00"
}