Siemens SIPROTEC 5 relays Buffer Copy Without Checking Size of Input (CVE-2021-33719)

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

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

if (description)
{
  script_id(500574);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/11");

  script_cve_id("CVE-2021-33719");

  script_name(english:"Siemens SIPROTEC 5 relays Buffer Copy Without Checking Size of Input (CVE-2021-33719)");

  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 SIPROTEC 5 relays with CPU variants CP050 (All versions < V8.80), SIPROTEC 5
relays with CPU variants CP100 (All versions < V8.80), SIPROTEC 5 relays with CPU variants CP300 (All versions < V8.80).
Specially crafted packets sent to port 4443/tcp could cause a Denial-of-Service condition or potential remote code
execution.  

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-847986.pdf");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-21-257-10");
  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:

- SIPROTEC 5 relays with CPU variants CP050, CP100, or CP300: Update to v8.80 or later.

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

- Block access to Port 4443/TCP, such as with an external firewall.

Siemens notes operators of critical power systems (e.g., TSOs or DSOs) worldwide are usually required by regulations to
build resilience into the power grids by applying multi-level redundant secondary protection schemes. Therefore, Siemens
recommends the operators check whether appropriate resilient protection measures are in place. The risk of cyber
incidents impacting the grid’s reliability can thus be minimized by virtue of the grid design.

Siemens strongly recommends applying the provided security updates using the corresponding tooling and documented
procedures made available with the product. If supported by the product, an automated means to apply the security
updates across multiple product instances may be used. Siemens strongly recommends prior validation of any security
update before being applied, and supervision, by trained staff, of the update process in the target environment.

As a general security measure Siemens strongly recommends protecting network access with appropriate mechanisms (e.g.,
firewalls, segmentation, VPN) and advises to configure the environment according to their operational guidelines in
order to run the devices in a protected IT environment.

Additional information on security guidelines for Digital Grid Products can be found
at:https://www.siemens.com/gridsecurity

Please see Siemens Security Advisory SSA-847986 for more information.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:H/I:H/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-2021-33719");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(120);

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/09/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/14");
  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:siprotec_5_with_cpu_variant_cp050");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siprotec_5_with_cpu_variant_cp100");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:siemens:siprotec_5_with_cpu_variant_cp300");
  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:siprotec_5_with_cpu_variant_cp050" :
        {"versionEndExcluding" : "8.80", "family" : "Siprotec5"},
    "cpe:/o:siemens:siprotec_5_with_cpu_variant_cp100" :
        {"versionEndExcluding" : "8.80", "family" : "Siprotec5"},
    "cpe:/o:siemens:siprotec_5_with_cpu_variant_cp300" :
        {"versionEndExcluding" : "8.80", "family" : "Siprotec5"}
};

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