Elasticsearch 9.0.x < 9.4.8 / 9.5.x < 9.5.5 DoS (ESA-2026-198)

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

include('compat.inc');

if (description)
{
  script_id(363431);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2026-103008");

  script_name(english:"Elasticsearch 9.0.x < 9.4.8 / 9.5.x < 9.5.5 DoS (ESA-2026-198)");

  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 9.0.x prior to 9.4.8, or 9.5.x prior to 9.5.5. It is,
therefore, affected by a vulnerability as referenced in the ESA-2026-198 advisory.

  - Uncontrolled Recursion (CWE-674) in Elasticsearch can lead to Denial of Service via a specially crafted
    request that causes the server to construct and process a deeply nested data structure with no bound on
    recursion depth. Elasticsearch contains an uncontrolled recursion weakness in how it builds and serializes
    geometry values produced by scripted runtime fields. Unlike geometry supplied as text, which is subject to
    a nesting-depth limit, geometry constructed from a script's output is not bounded. An authenticated user
    with read access to a single index can submit a request defining such a field with a script that produces
    a deeply nested structure. Processing this request recurses past the available stack space, causing the
    affected node to terminate. The node does not recover automatically on all deployments and may require
    manual intervention to restore service. (CVE-2026-103008)

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://discuss.elastic.co/t/390872");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Elasticsearch version 9.4.8, or 9.5.5 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-2026-103008");

  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:"2026/10/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/06");

  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:"generated_plugin", value:"current");
  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"
  },
  "checks": [
    {
      "product": {
        "name": "Elasticsearch",
        "type": "app"
      },
      "check_algorithm": "default",
      "constraints": [
        {
          "min_version": "9.0.0",
          "fixed_version": "9.4.8"
        },
        {
          "min_version": "9.5.0",
          "fixed_version": "9.5.5"
        }
      ]
    }
  ]
};

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