OpenVPN 2.6.x < 2.6.20 / 2.7.x < 2.7.2 TLS Race Condition

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(324955);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/03");

  script_cve_id("CVE-2026-40215");
  script_xref(name:"IAVA", value:"2026-A-0640");

  script_name(english:"OpenVPN 2.6.x < 2.6.20 / 2.7.x < 2.7.2 TLS Race Condition");

  script_set_attribute(attribute:"synopsis", value:
"An application installed on the remote host is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the version of OpenVPN installed on the remote host is affected by a
vulnerability:

  - A race condition in OpenVPN 2.6.0 through 2.6.19 and 2.7_alpha1 through 2.7.1 allows remote attackers to
    potentially cause a server crash or leak heap memory via a use-after-free triggered during TLS session
    promotion. (CVE-2026-40215)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://community.openvpn.net/Security%20Announcements/CVE-2026-40215
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7103b843");
  # https://community.openvpn.net/ReleaseHistory#openvpn-2620-released-22-april-2026
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2680c3aa");
  # https://community.openvpn.net/ReleaseHistory#openvpn-272-released-22-april-2026
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0dbd9e04");
  script_set_attribute(attribute:"solution", value:
"Upgrade to OpenVPN 2.6.20, 2.7.2, or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-40215");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/06/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/03");

  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:openvpn:openvpn");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("openvpn_server_installed.nbin");
  script_require_keys("installed_sw/OpenVPN Server");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'checks': [
    {
      'product': {'name': 'OpenVPN Server', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '2.6.0', 'fixed_version': '2.6.20'},
        {'min_version': '2.7.0', 'fixed_version': '2.7.2'}
      ]
    }
  ]
};

var vdf_result = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_WARNING);
vdf::handle_check_and_report_errors(vdf_result:vdf_result);