Hitachi ABB Power Grids AFS Series Loop with Unreachable Exit Condition (CVE-2020-9307)

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

include('compat.inc');

if (description)
{
  script_id(503961);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/21");

  script_cve_id("CVE-2020-9307");
  script_xref(name:"ICSA", value:"21-075-03");

  script_name(english:"Hitachi ABB Power Grids AFS Series Loop with Unreachable Exit Condition (CVE-2020-9307)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"AFS660/AFS665 Version 7.0.07 are affected by a denial of service vulnerability.
 An unauthenticated, adjacent attacker can cause an
infinite loop on one of the HSR ring ports of the device. This
effectively breaks the redundancy of the HSR ring. If the attacker can
perform the same attack on a second device, the ring is broken into
two parts (thus disrupting communication between devices in the
different parts).

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
# https://www.belden.com/dfsmedia/f1e38517e0cd4caa8b1acb6619890f5e/12276-source/options/view
# script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?83797cf6");
  script_set_attribute(attribute:"see_also", value:"https://www.belden.com/security");
  script_set_attribute(attribute:"see_also", value:"https://www.cisa.gov/news-events/ics-advisories/icsa-21-075-03");
  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.

Hitachi ABB Power Grids has published an advisory for AFS Series and advises users to update products with available
updates. The update removes the vulnerability by modifying the way the switch processes HSR frames.

For additional information and support, contact a product provider or Hitachi ABB Power Grids service organization. For
contact information, see Hitachi ABB Power Grids contact-centers.");
  script_set_cvss_base_vector("CVSS2#AV:A/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:A/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-2020-9307");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(835);

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/02/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/02/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/11/13");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:abb:afs660");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:abb:afs660-sr");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:abb:afs665");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:abb:afs665-sr");
  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) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/ABB");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/ABB');

var asset = tenable_ot::assets::get(vendor:'ABB');

var vuln_cpes = {
    "cpe:/o:abb:afs660" :
        {"versionEndIncluding" : "7.0.07", "versionStartIncluding" : "7.0.07", "family" : "AbbAFS"},
    "cpe:/o:abb:afs660-sr" :
        {"versionEndIncluding" : "7.0.07", "versionStartIncluding" : "7.0.07", "family" : "AbbAFS"},
    "cpe:/o:abb:afs665" :
        {"versionEndIncluding" : "7.0.07", "versionStartIncluding" : "7.0.07", "family" : "AbbAFS"},
    "cpe:/o:abb:afs665-sr" :
        {"versionEndIncluding" : "7.0.07", "versionStartIncluding" : "7.0.07", "family" : "AbbAFS"},
};

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