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Non-MFA account takeover via using only SSH public key to login in jumpserver

Type: advisorySources: OSV

JumpServer is an open source bastion host. As an unauthenticated user, it is possible to authenticate to the core API with a username and an SSH public key without needing a password or the corresponding SSH private key. An SSH public key should be considered public knowledge and should not used as an authentication secret alone. JumpServer provides an API for the KoKo component to validate user private key logins. This API does not verify the source of requests and will generate a personal authentication token. Given that public keys can be easily leaked, an attacker can exploit the leaked public key and username to authenticate, subsequently gaining access to the current user's information and authorized actions. This issue has been addressed in versions 2.28.20 and 3.7.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2023-43652
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 17:02 UTC · Revision 1

Source evidence

Non-MFA account takeover via using only SSH public key to login in jumpserver

core-osv · Original source

Published 27 Sept 2023, 18:31 UTC

JumpServer is an open source bastion host. As an unauthenticated user, it is possible to authenticate to the core API with a username and an SSH public key without needing a password or the corresponding SSH private key. An SSH public key should be considered public knowledge and should not used as an authentication secret alone. JumpServer provides an API for the KoKo component to validate user private key logins. This API does not verify the source of requests and will generate a personal authentication token. Given that public keys can be easily leaked, an attacker can exploit the leaked public key and username to authenticate, subsequently gaining access to the current user's information and authorized actions. This issue has been addressed in versions 2.28.20 and 3.7.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.

osv:CVE-2023-43652
Complete source record
{
  "id": "5d84ac496015ef61e791b6807985c38ad6af2ee340b7f2438700325c2646ba3c",
  "url": "https://osv.dev/vulnerability/CVE-2023-43652",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Non-MFA account takeover via using only SSH public key to login in jumpserver",
    "summary": "JumpServer is an open source bastion host. As an unauthenticated user, it is possible to authenticate to the core API with a username and an SSH public key without needing a password or the corresponding SSH private key. An SSH public key should be considered public knowledge and should not used as an authentication secret alone. JumpServer provides an API for the KoKo component to validate user private key logins. This API does not verify the source of requests and will generate a personal authentication token. Given that public keys can be easily leaked, an attacker can exploit the leaked public key and username to authenticate, subsequently gaining access to the current user's information and authorized actions. This issue has been addressed in versions 2.28.20 and 3.7.1. Users are advised to upgrade. There are no known workarounds for this vulnerability.",
    "evidence": "osv:CVE-2023-43652",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2023-43652",
      "aliases": [
        "CVE-2023-43652",
        "GHSA-fr8h-xh5x-r8g9"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/jumpserver/jumpserver",
              "type": "GIT",
              "events": [
                {
                  "introduced": "92fc0ceb1632b55e62a10a6aa8fcc6ecc7153cb0"
                },
                {
                  "fixed": "c28cca7ca20025d4793a7db9295280ca56841399"
                },
                {
                  "introduced": "7d3eb8c75d7edeb1cca3da25ae435acf678c4f69"
                },
                {
                  "fixed": "e75da94fc15a05e254132014b67be25c32c0cdc2"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:fit2cloud:jumpserver:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.0.0"
                      },
                      {
                        "fixed": "2.28.20"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:fit2cloud:jumpserver:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "3.0.0"
                      },
                      {
                        "fixed": "3.7.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-43652.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.151220737Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43652.json",
        "https://github.com/jumpserver/jumpserver/security/advisories/GHSA-fr8h-xh5x-r8g9",
        "https://nvd.nist.gov/vuln/detail/CVE-2023-43652",
        "https://www.sonarsource.com/blog/diving-into-jumpserver-attackers-gateway-to-internal-networks-1-2"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-862"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/43xxx/CVE-2023-43652.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2023-43652",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 505101,
  "published_at": "2023-09-27T18:31:41.32+00:00"
}