PN977 | MicroLogix 1100 Controllers Malformed Packet Denial of Service

Introduction

Description

Version 1.1 - April 3, 2019
Version 1.0 - May 18, 2017

A vulnerability exists in the MicroLogix™ 1100 controllers that, if successfully exploited, can cause a Denial of Service (DoS) condition. These controllers are used to control processes across several sectors, including without limitation: critical infrastructure; water/wastewater systems; entertainment; food and beverage; and automotive applications.

Customers using affected versions of this firmware are encouraged to evaluate the mitigations provided below, and apply the applicable mitigations to their deployed products. Additional details relating to this discovered vulnerability, including affected products and recommended countermeasures, are provided herein.

AFFECTED PRODUCTS

• Micrologix 1000 Controllers
  • 1763-L16BWA, 1763-L16AWA, 1763-L16BBB, 1763-L16DWD

VULNERABILITY DETAILS

A remote, unauthenticated attacker could send a single, specially crafted Programmable Controller Communication Commands (PCCC) packet to the controller that could potentially cause the controller to enter a Denial of Service (DoS) condition. PCCC messages are supported on Serial as well as Ethernet communication ports. The vulnerability is due to improper handling of PCCC messages.

CVE-2017-7924 has been assigned to this vulnerability. Rockwell Automation evaluated the vulnerability using the Common Vulnerability Scoring System ("CVSS") v3.0. A CVSS v3 base score of 7.5 has been assigned. For a better understanding of how this score was generated, please follow this link with the CVSS v3 vector string: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

RISK MITIGATIONS and RECOMMENDED USER ACTIONS

Customers using the affected controllers are encouraged to update to an available firmware revision that addresses the associated risk. Customers who are unable to update are directed toward risk mitigation strategies provided below, and are encouraged, when possible, to combine these with the general security guidelines to employ multiple strategies simultaneously.

GENERAL SECURITY GUIDELINES

1. Block all traffic to EtherNet/IP™ connected devices 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 Knowledgebase Article ID 898270.
2. Locate control system networks and devices behind firewalls, and isolate them from the business network.
3. 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 a VPN is only as secure as the connected devices that host them.

For further information on the Vulnerability Handling Process for Rockwell Automation, please refer to our Product Security Incident Response FAQ document.

Refer to our Industrial Network Architectures Page for comprehensive information about implementing validated architectures designed to deliver these measures.

Refer to the Network Services Overview Page for information on network and security services for Rockwell Automation to enable assessment, design, implementation and management of validated, secure network architectures.

We also recommend concerned customers continue to monitor this advisory by subscribing to updates on the Security Advisory Index for Rockwell Automation, located at: 54102 - Industrial Security Advisory Index. Customers may also reference the public Security page for Rockwell Automation for new and relevant information relating to this matter.

Rockwell Automation remains committed to making security enhancements to our systems in the future. For more information and for assistance with assessing the state of security of your existing control system, including improving your system-level security when using Rockwell Automation and other vendor controls products, you can visit the Rockwell Automation Security Solutions web site.

If you have questions regarding this notice, please send an email to our product security inbox at: Secure@ra.rockwell.com.

ADDITIONAL LINKS

• 54102 - Industrial Security Advisory Index
• Industrial Firewalls within a CPwE Architecture
• Deploying Industrial Firewalls within a CPwE Architecture Design and Implementation Guide

REVISION HISTORY

KCS Status