Siemens SIMATIC S7-1200 Improper Authentication (CVE-2021-37172)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(500575);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/09/04");

  script_cve_id("CVE-2021-37172");
  script_xref(name:"ICSA", value:"21-222-09");

  script_name(english:"Siemens SIMATIC S7-1200 Improper Authentication (CVE-2021-37172)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"A vulnerability has been identified in SIMATIC S7-1200 CPU family (incl. SIPLUS variants) (V4.5.0). Affected devices
fail to authenticate against configured passwords when provisioned using TIA Portal V13. This could allow an attacker
using TIA Portal V13 or later versions to bypass authentication and download arbitrary programs to the PLC. The
vulnerability does not occur when TIA Portal V13 SP1 or any later version was used to provision the device.   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/pdf/ssa-830194.pdf");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-21-222-09");
  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 released updates for the following products:

- S7-1200 CPU family (incl. SIPLUS variants): Update to v4.5.1 or later version

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

- Update to TIA Portal v13 SP1 or any later version before provisioning S7-1200 v4.5.0 devices.

As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate
mechanisms. In order to operate the devices in a protected IT environment, Siemens recommends users configure the
environment according to Siemens’ operational guidelines for industrial security and follow the recommendations in the
product manuals.

Additional information on industrial security by Siemens can be found at: https://www.siemens.com/industrialsecurity

For more information about this issue, please see Siemens Security Advisory SSA-830194");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  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:H/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-2021-37172");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(287);

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/08/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/08/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/02/07");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:simatic_s7-1200_cpu_firmware:4.5.0");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2022-2024 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_s7-1200_cpu_firmware:4.5.0" :
        {"versionEndIncluding" : "4.5.0", "versionStartIncluding" : "4.5.0", "family" : "S71200"}
};

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