Siemens SIMATIC Devices and SCALANCE Improper Certificate Validation (CVE-2024-41996)

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

include('compat.inc');

if (description)
{
  script_id(503709);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/03/05");

  script_cve_id("CVE-2024-41996");
  script_xref(name:"ICSA", value:"26-043-06");

  script_name(english:"Siemens SIMATIC Devices and SCALANCE Improper Certificate Validation (CVE-2024-41996)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"Validating the order of the public keys in the Diffie-Hellman Key
Agreement Protocol, when an approved safe prime is used, allows remote
attackers (from the client side) to trigger unnecessarily expensive
server-side DHE modular-exponentiation calculations. The client may
cause asymmetric resource consumption. The basic attack scenario is
that the client must claim that it can only communicate with DHE, and
the server must be configured to allow DHE and validate the order of
the public key.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-265688.html");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-26-043-06");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-089022.html");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  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_attribute(attribute:"cvss_score_source", value:"CVE-2024-41996");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(295);

  script_set_attribute(attribute:"vuln_publication_date", value:"2024/04/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/04/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/10/27");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1500_tm_mfp");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:scalance_xc-300_series_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:scalance_xr-300_series_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:scalance_xc-400_series_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:scalance_xr-500wg_series_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:scalance_xr-500_series_firmware");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tenable.ot");

  script_copyright(english:"This script is Copyright (C) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/Siemens");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Siemens');

var asset = tenable_ot::assets::get(vendor:'Siemens');

var vuln_cpes = {
    "cpe:/o:siemens:simatic_s7-1500_tm_mfp" :
        {"versionEndIncluding" : "1.1", "versionStartIncluding" : "1.1", "family" : "S71500", "orderNumbers": ["6ES7558-1AA00-0AB0"]},
    "cpe:/o:siemens:scalance_xc-300_series_firmware" :
        {"versionEndExcluding" : "3.3", "family" : "SCALANCEX300"},
    "cpe:/o:siemens:scalance_xr-300_series_firmware" :
        {"versionEndExcluding" : "3.3", "family" : "SCALANCEX300"},
    "cpe:/o:siemens:scalance_xc-400_series_firmware" :
        {"versionEndExcluding" : "3.3", "family" : "SCALANCEX400"},
    "cpe:/o:siemens:scalance_xr-500wg_series_firmware" :
        {"versionEndExcluding" : "3.3", "family" : "SCALANCEX500"},
    "cpe:/o:siemens:scalance_xr-500_series_firmware" :
        {"versionEndExcluding" : "3.3", "family" : "SCALANCEX500"}
};

tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_HOLE);