Rockwell Automation MicroLogix 1100 Improper Input Validation (CVE-2021-33012)

high Tenable OT Security Plugin ID 500542

Synopsis

The remote OT asset is affected by a vulnerability.

Description

Rockwell Automation MicroLogix 1100, all versions, allows a remote, unauthenticated attacker sending specially crafted commands to cause the PLC to fault when the controller is switched to RUN mode, which results in a denial-of-service condition. If successfully exploited, this vulnerability will cause the controller to fault whenever the controller is switched to RUN mode.

This plugin only works with Tenable.ot. Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

The following text was originally created by the Cybersecurity and Infrastructure Security Agency (CISA). The original can be found at CISA.gov.

A controller in this fault state can be recovered by downloading a new project or an offline copy of the project to the controller. Rockwell Automation recommends users set the controller switch to RUN mode to prevent remote programming.
Users are encouraged to have a backup copy of the project in the case it is necessary to recover from an event. Rockwell Automation also recommends users should consider migrating to the Micro870 controller.

Rockwell automation recommends the following general security guidelines:

- Utilize proper network infrastructure controls, such as firewalls, to help ensure EtherNet/IP traffic from unauthorized sources are blocked.
- Consult the product documentation for specific features, such as a hardware mode switch setting, to 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 Port 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 Knowledge Base Article BF7490
- 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 PN715
- 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), recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices.

Rockwell Automation users can refer to the Converged Plantwide Ethernet (CPwE) Design and Implementation Guide for best practices for deploying network segmentation and broader defense in depth strategies. Users can also refer to the Rockwell Automation System Security Design Guidelines on how to use Rockwell Automation products to improve the security of their industrial automation systems.

For more information see Rockwell Automation’s Security advisory (Login required).

Plugin Details

Severity: High

ID: 500542

Version: 1.9

Type: remote

Family: Tenable.ot

Published: 2/7/2022

Updated: 3/4/2024

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2021-33012

CVSS v3

Risk Factor: High

Base Score: 8.6

Temporal Score: 7.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:rockwellautomation:micrologix_1100_firmware

Required KB Items: Tenable.ot/Rockwell

Exploit Ease: No known exploits are available

Patch Publication Date: 7/9/2021

Vulnerability Publication Date: 7/9/2021

Reference Information

CVE: CVE-2021-33012

Detections

Analytics