Elasticsearch 5.x < 8.19.19 / 9.3.x < 9.3.8 / 9.4.x < 9.4.4 DoS (ESA-2026-75)

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

include('compat.inc');

if (description)
{
  script_id(338337);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/21");

  script_cve_id("CVE-2026-72683");

  script_name(english:"Elasticsearch 5.x < 8.19.19 / 9.3.x < 9.3.8 / 9.4.x < 9.4.4 DoS (ESA-2026-75)");

  script_set_attribute(attribute:"synopsis", value:
"The remote host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of Elasticsearch installed on the remote host is 5.x prior to 8.19.19, or 9.3.x prior to 9.3.8, or 9.4.x
prior to 9.4.4. It is, therefore, affected by a vulnerability as referenced in the ESA-2026-75 advisory.

  - A flaw in Elasticsearch allows an authenticated user with the privileges required to invoke the simulate
    pipeline API endpoint to submit a request that causes a self-referential data structure to be created. When a
    specific internal component later processes that structure, the operation recurses without bound and raises a
    fatal error that is not handled by the surrounding execution path, terminating the affected node process and
    resulting in a denial of service. (CVE-2026-72683)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://discuss.elastic.co/t/elasticsearch-8-19-19-9-3-8-9-4-4-security-update-esa-2026-75/389496
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2d8ac5b9");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Elasticsearch version 8.19.19, 9.3.8, or 9.4.4 or later as appropriate for your release branch.");
  script_set_attribute(attribute:"agent", value:"unix");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/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:"cvss_score_source", value:"CVE-2026-72683");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(674);

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/20");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:elasticsearch:elasticsearch");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:elastic:elasticsearch");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

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

  script_dependencies("elasticsearch_detect.nbin", "elastic_elasticsearch_nix_installed.nbin");
  script_require_keys("installed_sw/Elasticsearch");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'requires': [
    {'scope': 'target', 'match': {'os': 'linux'}}
  ],
  'checks': [
    {
      'product': {'name': 'Elasticsearch', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '5.0.0', 'fixed_version': '8.19.19'},
        {'min_version': '9.3.0', 'fixed_version': '9.3.8'},
        {'min_version': '9.4.0', 'fixed_version': '9.4.4'}
      ]
    }
  ]
};

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