Siemens LOGO! CMR and SIMATIC RTU 3000 Incorrect Calculation of Buffer Size (CVE-2020-36475)

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

include('compat.inc');

if (description)
{
  script_id(501676);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/12/19");

  script_cve_id("CVE-2020-36475");

  script_name(english:"Siemens LOGO! CMR and SIMATIC RTU 3000 Incorrect Calculation of Buffer Size (CVE-2020-36475)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9
LTS and before 2.7.18 LTS). The calculations performed by
mbedtls_mpi_exp_mod are not limited; thus, supplying overly large
parameters could lead to denial of service when generating Diffie-
Hellman key pairs.

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://github.com/ARMmbed/mbedtls/releases/tag/v2.16.9");
  script_set_attribute(attribute:"see_also", value:"https://github.com/ARMmbed/mbedtls/releases/tag/v2.25.0");
  script_set_attribute(attribute:"see_also", value:"https://github.com/ARMmbed/mbedtls/releases/tag/v2.7.18");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/pdf/ssa-756638.pdf");
  script_set_attribute(attribute:"see_also", value:"https://lists.debian.org/debian-lts-announce/2021/11/msg00021.html");
  script_set_attribute(attribute:"see_also", value:"https://lists.debian.org/debian-lts-announce/2022/12/msg00036.html");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-20");
  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.

For LOGO! CMR2020, Siemens recommends affected users update to v2.2 or later. 
For LOGO! CMR2040, Siemens recommends affected users update to v2.2 or later.

For the SIMATIC RTU 3000 family, Siemens recommends affected users use the certificate projection feature to pin the
valid certificates of external servers providing services to the RTU/CMR devices. Refer to the product manual for
further information.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  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-2020-36475");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(131);

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/08/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/08/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/09/21");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:logo%21_cmr2020_firmware");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:logo%21_cmr2040_firmware");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2023 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:logo%21_cmr2020_firmware" :
        {"versionEndExcluding" : "2.2", "family" : "LOGO!CM"},
    "cpe:/o:siemens:logo%21_cmr2040_firmware" :
        {"versionEndExcluding" : "2.2", "family" : "LOGO!CM"}
};

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