Siemens SIMATIC Devices Out-of-bounds Write (CVE-2025-21865)

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

include('compat.inc');

if (description)
{
  script_id(503686);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/14");

  script_cve_id("CVE-2025-21865");
  script_xref(name:"ICSA", value:"25-162-05");

  script_name(english:"Siemens SIMATIC Devices Out-of-bounds Write (CVE-2025-21865)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().
Commit eb28fd76c0a0 (gtp: Destroy device along with udp socket's
netns dismantle.) added the for_each_netdev() loop in
gtp_net_exit_batch_rtnl() to destroy devices in each netns as done in
geneve and ip tunnels. However, this could trigger ->dellink() twice
for the same device during ->exit_batch_rtnl().

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-082556.html");
  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-25-162-05");
  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 is preparing fixed versions and reports that currently, no fix is available.

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-082556 in HTML and CSAF.");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-21865");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(787);

  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_cpu_firmware:3.1.5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1500_tm_mfp");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siplus_s7-1500_cpu_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:simatic_s7-1500_cpu_firmware:3.1.5" :
        {"versionStartIncluding" : "3.1.5", "family" : "S71500", "orderNumbers" : ['6ES7518-4FX00-1AC0', '6ES7518-4AX00-1AB0', '6ES7518-4FX00-1AB0', '6ES7518-4AX00-1AC0']},
    "cpe:/o:siemens:siplus_s7-1500_cpu_firmware" :
        {"versionStartIncluding" : "3.1.5", "family" : "S71500", "orderNumbers" : ['6AG1518-4AX00-4AC0']}
};

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