Security advisory

{
  "id": "634b48e905c5ff7ad57c41b8ad2f16c85493cd6c7b718ed937d3b226e2427060",
  "url": "https://osv.dev/vulnerability/CVE-2020-27633",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-27633",
    "summary": "In FNET 4.6.3, TCP ISNs are improperly random.",
    "evidence": "osv:CVE-2020-27633",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2020-27633",
      "aliases": [
        "CVE-2020-27633"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/butok/fnet",
              "type": "GIT",
              "events": [
                {
                  "introduced": "fb3c86df5573af27e119f5c7dfc7aa5bd52475a2"
                },
                {
                  "last_affected": "fb3c86df5573af27e119f5c7dfc7aa5bd52475a2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:butok:fnet:4.6.3:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.6.3"
                      },
                      {
                        "last_affected": "4.6.3"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.6.3",
            "v4.6.3"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-27633.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:30.546270185Z",
      "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-2020-27633",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 432594,
  "published_at": "2023-10-10T17:15:10.607+00:00"
}