OpenVPN 2.5.0 < 2.5.12 / 2.6.0 < 2.6.21 / 2.7.x < 2.7.5 Memory Leak DoS

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

include('compat.inc');

if (description)
{
  script_id(325893);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/10");

  script_cve_id("CVE-2026-13698");

  script_name(english:"OpenVPN 2.5.0 < 2.5.12 / 2.6.0 < 2.6.21 / 2.7.x < 2.7.5 Memory Leak DoS");

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

  - A memory leak in tls-crypt-v2 client key handling allows remote attackers with a valid tls-crypt-v2
    client key to potentially cause a denial of service via out-of-memory conditions and subsequent server
    crashes. (CVE-2026-13698)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://github.com/OpenVPN/openvpn/releases/tag/v2.6.21");
  script_set_attribute(attribute:"see_also", value:"https://github.com/OpenVPN/openvpn/releases/tag/v2.7.5");
  script_set_attribute(attribute:"solution", value:
"Upgrade to OpenVPN 2.6.21, 2.7.5, or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-13698");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/07/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/09");

  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'},
  'requires': [
    {'scope': 'target', 'match': {'os': 'windows'}}
  ],
  'checks': [
    {
      'product': {'name': 'OpenVPN Server', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '2.5.0', 'max_version': '2.5.11', 'fixed_display': 'Refer to vendor advisory'},
        {'min_version': '2.6.0', 'fixed_version': '2.6.21'},
        {'min_version': '2.7_alpha1', 'fixed_version': '2.7.5'}
      ]
    }
  ]
};

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