Security advisory

{
  "id": "cb9ef4e9f40473144f335b8f3caf87b7a4f3b00e545a8ccd6aae3a6cb43d6e4c",
  "url": "https://osv.dev/vulnerability/CVE-2020-27222",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-27222",
    "summary": "In Eclipse Californium version 2.3.0 to 2.6.0, the certificate based (x509 and RPK) DTLS handshakes accidentally fails, because the DTLS server side sticks to a wrong internal state. That wrong internal state is set by a previous certificate based DTLS handshake failure with TLS parameter mismatch. The DTLS server side must be restarted to recover this. This allow clients to force a DoS.",
    "evidence": "osv:CVE-2020-27222",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2020-27222",
      "aliases": [
        "CVE-2020-27222"
      ],
      "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/eclipse-californium/californium",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ced7ef98f325b62a1d23011e0bc67b1bdd662293"
                },
                {
                  "last_affected": "864c58f817e2d2a403c6a7bf54e75fbc5c408dbe"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:eclipse:californium:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.3.0"
                      },
                      {
                        "last_affected": "2.6.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.6.0",
            "2.5.0",
            "2.4.0",
            "2.3.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-27222.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:39.089549740Z",
      "provider": "osv",
      "references": [
        "https://bugs.eclipse.org/bugs/show_bug.cgi?id=570844"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-27222",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 434591,
  "published_at": "2021-02-03T16:15:13.117+00:00"
}