Security advisory

{
  "id": "28dd9b8c55920fc67dba261c62e04814102b32a3d16f6bad8285c2aa97cc3e5b",
  "url": "https://osv.dev/vulnerability/CVE-2021-23270",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-23270",
    "summary": "In Gargoyle OS 1.12.0, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set.",
    "evidence": "osv:CVE-2021-23270",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-23270",
      "aliases": [
        "CVE-2021-23270"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ericpaulbishop/gargoyle",
              "type": "GIT",
              "events": [
                {
                  "introduced": "73ff591ced92f40b8c84f83883e872ec377cfa84"
                },
                {
                  "last_affected": "73ff591ced92f40b8c84f83883e872ec377cfa84"
                },
                {
                  "fixed": "24afe944a6ffff53d84a748384e276a4e95912ec"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:gargoyle-router:gargoyle:1.12.0:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.12.0"
                      },
                      {
                        "last_affected": "1.12.0"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "24afe944a6ffff53d84a748384e276a4e95912ec"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.12.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-23270.json"
          }
        }
      ],
      "modified": "2026-10-20T10:54:32.583112804Z",
      "provider": "osv",
      "references": [
        "https://github.com/ericpaulbishop/gargoyle/commit/24afe944a6ffff53d84a748384e276a4e95912ec"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-23270",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 385532,
  "published_at": "2021-04-12T19:15:14.517+00:00"
}