Security advisory

{
  "id": "84d1b2e0669a889949f4fda23e1324655c2819e5b17041d630305890af6191f4",
  "url": "https://osv.dev/vulnerability/CVE-2021-44273",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2021-44273",
    "summary": "e2guardian v5.4.x <= v5.4.3r is affected by missing SSL certificate validation in the SSL MITM engine. In standalone mode (i.e., acting as a proxy or a transparent proxy), with SSL MITM enabled, e2guardian, if built with OpenSSL v1.1.x, did not validate hostnames in certificates of the web servers that it connected to, and thus was itself vulnerable to MITM attacks.",
    "evidence": "osv:CVE-2021-44273",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2021-44273",
      "aliases": [
        "CVE-2021-44273"
      ],
      "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/e2guardian/e2guardian",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "3ce57b50c9754bca39fabd1eaa1b69f0bbe223f9"
                },
                {
                  "fixed": "eae46a7e2a57103aadca903c4a24cca94dc502a2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:e2bn:e2guardian:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "5.4.0"
                      },
                      {
                        "last_affected": "5.4.3r"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "eae46a7e2a57103aadca903c4a24cca94dc502a2"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v5.4.3r",
            "v5.4.2r-pre2",
            "v5.4.1-pre1",
            "v5.3.2",
            "v5.2.0",
            "v5.0.0beta",
            "v4.0-beta0",
            "v3.1.1",
            "v3.1.0",
            "v3.0.2",
            "v3.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-44273.json",
            "vanir_signatures": [
              {
                "id": "CVE-2021-44273-79006267",
                "digest": {
                  "length": 2340,
                  "function_hash": "225020943847239974401407156376740454469"
                },
                "source": "https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2",
                "target": {
                  "file": "src/Socket.cpp",
                  "function": "Socket::startSslClient"
                },
                "deprecated": false,
                "signature_type": "Function",
                "signature_version": "v1"
              },
              {
                "id": "CVE-2021-44273-a848bf47",
                "digest": {
                  "threshold": 0.9,
                  "line_hashes": [
                    "51099355436612688877461331241952407539",
                    "84869958030245548021741248928003404760",
                    "311604252843514328573653834232659919309",
                    "245098895109109632988598352585023675897"
                  ]
                },
                "source": "https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2",
                "target": {
                  "file": "src/Socket.cpp"
                },
                "deprecated": false,
                "signature_type": "Line",
                "signature_version": "v1"
              }
            ],
            "vanir_signatures_modified": "2026-10-20T14:30:05Z"
          }
        }
      ],
      "modified": "2026-10-20T14:30:05.168788921Z",
      "provider": "osv",
      "references": [
        "https://lists.debian.org/debian-lts-announce/2023/09/msg00010.html",
        "https://github.com/e2guardian/e2guardian/commit/eae46a7e2a57103aadca903c4a24cca94dc502a2",
        "https://github.com/e2guardian/e2guardian/issues/707"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2021-44273",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 389107,
  "published_at": "2021-12-23T12:15:07.387+00:00"
}