Rockwell Automation MicroLogix 1400 Buffer Copy Without Checking Size of Input (CVE-2021-22659)

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

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

if (description)
{
  script_id(500469);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/04/11");

  script_cve_id("CVE-2021-22659");

  script_name(english:"Rockwell Automation MicroLogix 1400 Buffer Copy Without Checking Size of Input (CVE-2021-22659)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"Rockwell Automation MicroLogix 1400 Version 21.6 and below may allow a remote unauthenticated attacker to send a
specially crafted Modbus packet allowing the attacker to retrieve or modify random values in the register. If
successfully exploited, this may lead to a buffer overflow resulting in a denial-of-service condition. The FAULT LED
will flash RED and communications may be lost. Recovery from denial-of-service condition requires the fault to be
cleared by the user.  

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://us-cert.cisa.gov/ics/advisories/icsa-21-033-01");
  # https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129877/loc/en_US#__highlight
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?3c5f13d4");
  # https://www.rockwellautomation.com/en-us/support/advisory.PN1545.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b3880b18");
  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.

Rockwell Automation recommends users with the affected controller to mitigate risk. They encourage, when possible, to
combine this guidance with the general security guidelines for a comprehensive defense-in-depth strategy. Please
subscribe to updates to this advisory and the Industrial Security Advisory Index to stay notified.

All users, if applicable, may disable Modbus TCP support if it is not necessary for their MicroLogix 1400
implementation. Without Modbus TCP enabled, a potential attacker does not have access to exploit the device using this
vulnerability.

For additional information see Rockwell Automation Security Advisory PN1545.

Rockwell Automation recommends the following network-based vulnerability mitigations for embedded products:

- Utilize proper network infrastructure controls (such as firewalls) to help ensure Modbus TCP from unauthorized sources
are blocked.
- Consult the product documentation for specific features (such as a hardware keyswitch setting), which may be used to
block unauthorized changes, etc.
- Block all traffic to EtherNet/IP or other CIP protocol-based devices from outside the manufacturing zone by blocking
or restricting access to TCP and UDP Port 2222 and 44818 using proper network infrastructure controls, such as
firewalls, UTM devices, or other security appliances. For more information on TCP/UDP ports used by Rockwell Automation
products, see Knowledgebase Article ID 898270.

Rockwell Automation recommends the following software/PC-based mitigation strategies:

- Run all software as a User, not as an Administrator, to minimize the impact of malicious code on the infected system.
- Use of Microsoft AppLocker or other similar allow list application can help mitigate risk. Information on using
AppLocker with Rockwell Automation products is available at Knowledgebase Article ID 546989.
- Ensure the least-privilege user principle is followed, and user/service account access to shared resources (such as a
database) is only granted with a minimum of rights as needed.

Rockwell Automation recommends the following general mitigations:

- Use trusted software, software patches, antivirus/antimalware programs, and interact only with trusted websites and
attachments.
- Minimize network exposure for all control system devices and/or systems and ensure they are not accessible from the
Internet. For further information about the risks of unprotected Internet accessible control systems, please see
Knowledgebase Article ID 494865.
- Locate control system networks and devices behind firewalls and isolate them from the business network.
- When remote access is required, use secure methods, such as virtual private networks (VPNs), and recognize VPNs may
have vulnerabilities and should be updated to the most current version available. Also recognize a VPN is only as secure
as the connected devices.");
  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:L/I:L/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-2021-22659");

  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:"2021/03/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/25");
  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:rockwellautomation:micrologix_1400_firmware");
  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/Rockwell");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Rockwell');

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

var vuln_cpes = {
    "cpe:/o:rockwellautomation:micrologix_1400_firmware" :
        {"versionEndIncluding" : "21.6", "family" : "MicroLogix1400"}
};

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