Security advisory

{
  "id": "34610d3d45084a4ae124555c91b9088cd6526804f3c07cbebc60b0a5a1d22527",
  "url": "https://osv.dev/vulnerability/CVE-2021-3547",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-3547",
    "summary": "OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.",
    "evidence": "osv:CVE-2021-3547",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-3547",
      "aliases": [
        "CVE-2021-3547"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/openvpn/openvpn3",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1e6208e102ea6781710401d71fffe017658dcedf"
                },
                {
                  "last_affected": "861fe85afb66bc593ec4ae138fd42b1553b892ad"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:openvpn:openvpn:3.6:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.6"
                      },
                      {
                        "last_affected": "3.6"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "cpe": "cpe:2.3:a:openvpn:openvpn:3.6.1:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.6.1"
                      },
                      {
                        "last_affected": "3.6.1"
                      }
                    ],
                    "source": "CPE_STRING"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.6",
            "3.6.1",
            "release/3.6.1",
            "release/3.6"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-3547.json"
          }
        }
      ],
      "modified": "2026-10-24T10:31:01.021261648Z",
      "provider": "osv",
      "references": [
        "https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements",
        "https://community.openvpn.net/openvpn/wiki/CVE-2021-3547"
      ],
      "provider_metadata": {
        "unresolved_ranges": [
          {
            "cpes": [
              "cpe:2.3:a:openvpn:openvpn:3.6.1:*:*:*:*:*:*:*",
              "cpe:2.3:a:openvpn:openvpn:3.6:*:*:*:*:*:*:*"
            ],
            "vendor_product": "openvpn:openvpn",
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "3.6"
                  },
                  {
                    "last_affected": "3.6"
                  },
                  {
                    "introduced": "3.6.1"
                  },
                  {
                    "last_affected": "3.6.1"
                  }
                ],
                "source": "CPE_STRING"
              }
            ]
          }
        ]
      }
    },
    "related_cves": [
      {
        "value": "CVE-2021-3547",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 439697,
  "published_at": "2021-07-12T11:15:08.233+00:00"
}