Security advisory

{
  "id": "0566093c6e293376436917e0a37561e68f67f2358fc0c7b3f743f1723c4ad015",
  "url": "https://osv.dev/vulnerability/CVE-2021-34433",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-34433",
    "summary": "In Eclipse Californium version 2.0.0 to 2.6.4 and 3.0.0-M1 to 3.0.0-M3, the certificate based (x509 and RPK) DTLS handshakes accidentally succeeds without verifying the server side's signature on the client side, if that signature is not included in the server's ServerKeyExchange.",
    "evidence": "osv:CVE-2021-34433",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-34433",
      "aliases": [
        "CVE-2021-34433"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/eclipse-californium/californium",
              "type": "GIT",
              "events": [
                {
                  "introduced": "15a27a972d7b4dd8d28d717cedfd01e6bf860e38"
                },
                {
                  "fixed": "896b12c5a582787bed4dc971b0b0f675009b2401"
                },
                {
                  "introduced": "8f6f689bcc03377f682d8c3b86c705ce02225afd"
                },
                {
                  "last_affected": "b5780bb2e17efb708e46242a204094ff1cdad034"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:eclipse:californium:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.0.0"
                      },
                      {
                        "fixed": "2.6.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:eclipse:californium:3.0.0:m1:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0-m1"
                      },
                      {
                        "last_affected": "3.0.0-m1"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:eclipse:californium:3.0.0:m2:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0-m2"
                      },
                      {
                        "last_affected": "3.0.0-m2"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:eclipse:californium:3.0.0:m3:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0-m3"
                      },
                      {
                        "last_affected": "3.0.0-m3"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.0.0-m1",
            "3.0.0-m2",
            "3.0.0-m3",
            "3.0.0-M3",
            "2.6.4",
            "3.0.0-M2",
            "2.6.3",
            "3.0.0-M1",
            "2.6.2",
            "2.6.1",
            "2.6.0",
            "2.5.0",
            "2.4.0",
            "2.3.0",
            "2.3.0-RC2",
            "2.3.0-RC1",
            "2.2.0",
            "2.2.0-RC1",
            "2.1.0",
            "2.1.0-RC2",
            "2.1.0-RC1",
            "2.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-34433.json"
          }
        }
      ],
      "modified": "2026-10-24T10:30:47.610722420Z",
      "provider": "osv",
      "references": [
        "https://bugs.eclipse.org/bugs/show_bug.cgi?id=575281"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-34433",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 436580,
  "published_at": "2021-08-20T17:15:07.687+00:00"
}