Siemens SIMATIC S7-1500 Missing Cryptographic Step (CVE-2025-69418)

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

include('compat.inc');

if (description)
{
  script_id(505147);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/02/16");

  script_cve_id("CVE-2025-69418");

  script_name(english:"Siemens SIMATIC S7-1500 Missing Cryptographic Step (CVE-2025-69418)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"Issue summary: When using the low-level OCB API directly with AES-NI
or<br>other hardware-accelerated code paths, inputs whose length is
not a multiple<br>of 16 bytes can leave the final partial block
unencrypted and unauthenticated.<br><br>Impact summary: The trailing
1-15 bytes of a message may be exposed in<br>cleartext on encryption
and are not covered by the authentication tag,<br>allowing an attacker
to read or tamper with those bytes without detection.<br><br>The low-
level OCB encrypt and decrypt routines in the hardware-
accelerated<br>stream path process full 16-byte blocks but do not
advance the input/output<br>pointers. The subsequent tail-handling
code then operates on the original<br>base pointers, effectively
reprocessing the beginning of the buffer while<br>leaving the actual
trailing bytes unprocessed. The authentication checksum<br>also
excludes the true tail bytes.<br><br>However, typical OpenSSL
consumers using EVP are not affected because the<br>higher-level EVP
and provider OCB implementations split inputs so that full<br>blocks
and trailing partial blocks are processed in separate calls,
avoiding<br>the problematic code path. Additionally, TLS does not use
OCB ciphersuites.<br>The vulnerability only affects applications that
call the low-level<br>CRYPTO_ocb128_encrypt() or
CRYPTO_ocb128_decrypt() functions directly with<br>non-block-aligned
lengths in a single call on hardware-accelerated builds.<br>For these
reasons the issue was assessed as Low severity.<br><br>The FIPS
modules in 3.6, 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected<br>by
this issue, as OCB mode is not a FIPS-approved
algorithm.<br><br>OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are
vulnerable to this issue.<br><br>OpenSSL 1.0.2 is not affected by this
issue.

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:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-69418");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(325);

  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:"2026/02/13");

  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_WARNING);