Siemens SIMATIC ET 200SP Communication Processors Missing Authentication For Critical Function (CVE-2025-40771)

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

include('compat.inc');

if (description)
{
  script_id(503756);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/12");

  script_cve_id("CVE-2025-40771");
  script_xref(name:"ICSA", value:"25-289-07");

  script_name(english:"Siemens SIMATIC ET 200SP Communication Processors Missing Authentication For Critical Function (CVE-2025-40771)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"Affected devices do not properly authenticate configuration
connections. This could allow an unauthenticated remote attacker to
access the configuration data.

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-486936.html");
  script_set_attribute(attribute:"see_also", value:"https://support.industry.siemens.com/cs/ww/en/view/109995159/");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-25-289-07");
  script_set_attribute(attribute:"solution", value:
"The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original
can be found at CISA.gov.

Siemens has identified the following specific workarounds and mitigations users can apply to reduce risk:

- All affected products: Restrict access to the affected systems to trusted IP addresses only
- All affected products: Update to V2.4.24 or later version

As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To
operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens'
operational guidelines for industrial security and following recommendations in the product manuals.

Additional information on industrial security by Siemens can be found on the Siemens industrial security webpage

For more information see the associated Siemens security advisory SSA-486936 in HTML and CSAF.");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-40771");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(306);

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/10/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/10/14");
  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_cp_1542sp-1_firmware:2.4.24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1542sp-1_irc_firmware:2.4.24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_cp_1543sp-1_firmware:2.4.24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_et_200sp_cp_1542sp-1_irc_tx_rail_firmware:2.4.24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_firmware:2.4.24");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_tx_rail_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_cp_1542sp-1_firmware:2.4.24" :
        {"versionEndExcluding" : "2.4.24", "family" : "S71500", "orderNumbers" : ['6GK7542-6UX00-0XE0']},
    "cpe:/o:siemens:simatic_cp_1542sp-1_irc_firmware:2.4.24" :
        {"versionEndExcluding" : "2.4.24", "family" : "S71500", "orderNumbers" : ['6GK7542-6VX00-0XE0']},
    "cpe:/o:siemens:simatic_cp_1543sp-1_firmware:2.4.24" :
        {"versionEndExcluding" : "2.4.24", "family" : "S71500", "orderNumbers" : ['6GK7543-6WX00-0XE0']},
    "cpe:/o:siemens:siplus_et_200sp_cp_1542sp-1_irc_tx_rail_firmware:2.4.24" :
        {"versionEndExcluding" : "2.4.24", "family" : "ET200", "orderNumbers" : ['6AG2542-6VX00-4XE0']},
    "cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_firmware:2.4.24" :
        {"versionEndExcluding" : "2.4.24", "family" : "ET200", "orderNumbers" : ['6AG1543-6WX00-7XE0']},
    "cpe:/o:siemens:siplus_et_200sp_cp_1543sp-1_isec_tx_rail_firmware" :
        {"versionEndExcluding" : "2.4.24", "family" : "ET200", "orderNumbers" : ['6AG2543-6WX00-4XE0']}
};

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