Siemens SIMATIC S7-1500 TM MFP NULL Pointer Dereference (CVE-2026-28389)

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

include('compat.inc');

if (description)
{
  script_id(505456);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/17");

  script_cve_id("CVE-2026-28389");
  script_xref(name:"ICSA", value:"26-134-10");

  script_name(english:"Siemens SIMATIC S7-1500 TM MFP NULL Pointer Dereference (CVE-2026-28389)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"Issue summary: During processing of a crafted CMS EnvelopedData
message with KeyAgreeRecipientInfo a NULL pointer dereference can
happen.  Impact summary: Applications that process attacker-controlled
CMS data may crash before authentication or cryptographic operations
occur resulting in Denial of Service.  When a CMS EnvelopedData
message that uses KeyAgreeRecipientInfo is processed, the optional
parameters field of KeyEncryptionAlgorithmIdentifier is examined
without checking for its presence. This results in a NULL pointer
dereference if the field is missing.  Applications and services that
call CMS_decrypt() on untrusted input (e.g., S/MIME processing or CMS-
based protocols) are vulnerable.  The FIPS modules in 3.6, 3.5, 3.4,
3.3 and 3.0 are not affected by this issue, as the affected code is
outside the OpenSSL FIPS module boundary.

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-032379.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://support.industry.siemens.com/cs/ww/en/view/109814144/");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/ICSA-26-134-10");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/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:N/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-2026-28389");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(476);

  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:"2026/06/18");

  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:"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) 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"]}
};

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