Security advisory

{
  "id": "60662886d49edc69b7d7e99bc56a4ef96109d754caa3fca2ed78b294391d9e89",
  "url": "https://osv.dev/vulnerability/CVE-2020-27631",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-27631",
    "summary": "In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.",
    "evidence": "osv:CVE-2020-27631",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2020-27631",
      "aliases": [
        "CVE-2020-27631"
      ],
      "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/oryx-embedded/cyclonetcp",
              "type": "GIT",
              "events": [
                {
                  "introduced": "21fb9364b397deac4cb940c733e09cf34ec57b9c"
                },
                {
                  "last_affected": "21fb9364b397deac4cb940c733e09cf34ec57b9c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:oryx-embedded:cyclonetcp:1.9.6:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "1.9.6"
                      },
                      {
                        "last_affected": "1.9.6"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "1.9.6",
            "v1.9.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-27631.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:27.222164213Z",
      "provider": "osv",
      "references": [
        "https://www.cisa.gov/news-events/ics-advisories/icsa-21-042-01",
        "https://www.forescout.com",
        "https://www.forescout.com/resources/numberjack-weak-isn-generation-in-embedded-tcpip-stacks/"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-27631",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 431786,
  "published_at": "2023-10-10T17:15:10.453+00:00"
}