Security advisory

{
  "id": "f94f1ff2cb62fe36d7bb2c196c57aae126f52285731411cf6eb10097b7925173",
  "url": "https://osv.dev/vulnerability/CVE-2021-22881",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-22881",
    "summary": "The Host Authorization middleware in Action Pack before 6.1.2.1, 6.0.3.5 suffers from an open redirect vulnerability. Specially crafted `Host` headers in combination with certain \"allowed host\" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website. Impacted applications will have allowed hosts with a leading dot. When an allowed host contains a leading dot, a specially crafted `Host` header can be used to redirect to a malicious website.",
    "evidence": "osv:CVE-2021-22881",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2021-22881",
      "aliases": [
        "CVE-2021-22881",
        "GHSA-8877-prq4-9xfw"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/rails/rails",
              "type": "GIT",
              "events": [
                {
                  "introduced": "66cabeda2c46c582d19738e1318be8d59584cc5b"
                },
                {
                  "fixed": "c5929d5eb55b749bc124b3ccc2d79323d015701f"
                },
                {
                  "introduced": "914caca2d31bd753f47f9168f2a375921d9e91cc"
                },
                {
                  "fixed": "130c128eae233bf71231c73b9c3c3b3f3ede918b"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.0.0"
                      },
                      {
                        "fixed": "6.0.3.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:rubyonrails:rails:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "6.1.0"
                      },
                      {
                        "fixed": "6.1.2.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v6.1.2",
            "v6.0.3.4",
            "v6.1.1",
            "v6.1.0",
            "v6.0.3.3",
            "v6.0.3.2",
            "v6.0.3.1",
            "v6.0.3",
            "v6.0.3.rc1",
            "v6.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-22881.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:27.456654228Z",
      "provider": "osv",
      "references": [
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XQ3NS4IBYE2I3MVMGAHFZBZBIZGHXHT3/",
        "https://benjamin-bouchet.com/cve-2021-22881-faille-de-securite-dans-le-middleware-hostauthorization/",
        "https://discuss.rubyonrails.org/t/cve-2021-22881-possible-open-redirect-in-host-authorization-middleware/77130",
        "https://hackerone.com/reports/1047447"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*"
            ],
            "vendor_product": "fedoraproject:fedora",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "33"
                  },
                  {
                    "last_affected": "33"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-22881",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 431832,
  "published_at": "2021-02-11T18:15:17.46+00:00"
}