Rockwell Automation Logix Controllers (Update A)

1. EXECUTIVE SUMMARY

• CVSS v3 10.0
• ATTENTION: Exploitable remotely/low skill level to exploit
• Vendor: Rockwell Automation
• Equipment: Studio 5000 Logix Designer, RSLogix 5000, Logix Controllers
• Vulnerability: Insufficiently Protected Credentials

2. UPDATE INFORMATION

This updated advisory is a follow-up to the original advisory titled ICSA-21-056-03 Rockwell Automation Logix Controllers that was published February 25, 2021, to the ICS webpage on us-cert.cisa.gov.

3. RISK EVALUATION

Successful exploitation of this vulnerability could allow a remote unauthenticated attacker to bypass the verification mechanism and connect with Logix controllers. Additionally, this vulnerability could enable an unauthorized third-party tool to alter the controller’s configuration and/or application code.

4. TECHNICAL DETAILS

4.1 AFFECTED PRODUCTS

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The following versions of Rockwell software are affected:

• RSLogix 5000: Versions 16 through 20
• Studio 5000 Logix Designer: Versions 21 and later
• FactoryTalk Security, part of the FactoryTalk Services Platform, if configured and deployed v2.10 and later

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The following Rockwell Logix Controllers are affected:

• CompactLogix 1768
• CompactLogix 1769
• CompactLogix 5370
• CompactLogix 5380
• CompactLogix 5480
• ControlLogix 5550
• ControlLogix 5560
• ControlLogix 5570
• ControlLogix 5580
• DriveLogix 5560
• DriveLogix 5730
• DriveLogix 1794-L34
• Compact GuardLogix 5370
• Compact GuardLogix 5380
• GuardLogix 5570
• GuardLogix 5580
• SoftLogix 5800

4.2 VULNERABILITY OVERVIEW

4.2.1    INSUFFICIENTLY PROTECTED CREDENTIALS CWE-522

Studio 5000 Logix Designer uses a key to verify Logix controllers are communicating with the affected Rockwell Automation products. The product is vulnerable because an unauthenticated attacker could bypass this verification mechanism and authenticate with Logix controllers.

CVE-2021-22681 has been assigned to this vulnerability. A CVSS v3 base score of 10.0 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H).

4.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Multiple
• COUNTRIES/AREAS DEPLOYED: Worldwide
• COMPANY HEADQUARTERS LOCATION: United States

4.4 RESEARCHER

The vulnerability was independently co-discovered by Lab. of Information Systems Security Assurance (Eunseon Jeong, Youngho An, Junyoung Park, Insu Oh, Kangbin Yim) of Soonchunhyang University, Kaspersky, and Sharon Brizinov and Tal Keren of Claroty.

5. MITIGATIONS

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Rockwell Automation has determined this vulnerability cannot be mitigated with a patch. Rockwell encourages users to combine its specific risk mitigation recommendations with general security guidelines for a comprehensive defense-in-depth strategy.

A comprehensive defense-in-depth strategy can reduce the risk of this vulnerability. To reduce risk, Rockwell recommends users ensure they are employing proper network segmentation and security controls; including, but not limited to:

• Minimizing network exposure for all control system devices and/or systems and confirm these devices are not accessible from the Internet.
• Locating control system networks and devices behind firewalls and isolating them from the enterprise/business network.
• Restricting or blocking traffic on TCP 44818 from outside of the industrial control system network zone. For more information on the TCP/UDP ports used by Rockwell Automation products, see BF7490 (login required). 
• When remote access is required, use secure methods such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. VPN is only as secure as the connected devices.

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

Common Industrial Protocol (CIP) Security mitigates this vulnerability as it provides the ability to deploy TLS- and DTLS-based secure communications to supported products. CIP Security is an enhancement to the ODVA (Open DeviceNet Vendors Association) EtherNet/IP industrial communication standard and directly addresses this vulnerability. CIP Security allows users to leverage and manage certificates and/or pre-shared keys, and does not make use of any hardcoded keys.

Users requiring setup or deployment guidance for CIP Security protocol should refer to the CIP Security deployment reference guide.

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Additionally, Rockwell recommends users follow the following risk mitigation and recommended user actions for the following product family and versions:

• ControlLogix 5580 v32 or later:
  • Put controller’s mode switch to “Run” mode.
  • If the above cannot be deployed, the followings mitigations are recommended:
    • Deploy CIP Security for Logix Designer connections through the front port. CIP Security prevents unauthorized connection when deployed properly.
    • If not using the front port, use a 1756-EN4TR ControlLogix Ethernet/IP Module and deploy CIP Security. The 1756-EN4TR supports CIP Security which prevents unauthorized connections when properly deployed.
• ControlLogix 5580 v31:
  • Put controller’s mode switch to “Run” mode.
  • If the above cannot be deployed, the following mitigations are recommended:
    • Apply v32 or later and follow mitigations actions outlined above.
    • If unable to apply a newer version, use a 1756-EN4TR ControlLogix EtherNet/IP Module and deploy CIP Security. The 1756-EN4TR supports CIP Security, which prevents unauthorized connections when properly deployed.
• ControlLogix 5570 v31 or later:
  • Put controller’s mode switch to “Run” mode.
  • If the above cannot be deployed, the following mitigations are recommended:
    • Use a 1756-EN4TR ControlLogix EtherNet/IP Module and deploy CIP Security. The 1756-EN4TR supports CIP Security, which prevents unauthorized connections when properly deployed.
• ControlLogix 5580 v28-v30, ControlLogix 5570 v18 or later, ControlLogix 5560 v16 or later, ControlLogix 5550 v16, GuardLogix 5580 v31 or later, GuardLogix 5570 v20 or later, GuardLogix 5560 v16 or later, 1768 CompactLogix v16 or later, 1769 CompactLogix v16 or later, CompactLogix 5370 v20 or later, CompactLogix 5380 v28 or later, CompactLogix 5480 v32 or later, Compact GuardLogix 5370 v28 or later, Compact GuardLogix 5380 v31 or later, FlexLogix 1794-L34 v16, DriveLogix 5370 v16 or later.
  • Put controller’s mode switch to “Run” mode.
• SoftLogix 5800: No additional mitigation available. Follow the Converged Plantwide Ethernet (CPwE) Design and Implementation Guide.

In addition, Rockwell recommends users employ the following methods to detect changes to configuration or application files:

• Monitor controller change log for any unexpected modifications or anomalous activity.
• If using v17 or later, utilize the Controller Log feature.
• If using v20 or later, utilize Change Detection in the Logix Designer Application.
• If available, use the functionality in Factory Talk AssetCentre to detect changes.

Rockwell Automation has published a security advisory that further describes how this vulnerability affects the Studio 5000 Logix Designer software and associated controllers.

Requests for additional information can be sent to the Rockwell RASecure Inbox (rasecure@ra.rockwell.com).

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability. Specifically, users should:

• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote 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 VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize VPN is only as secure as the connected devices.

CISA reminds organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.



CISA also provides a section for control systems security recommended practices on the ICS webpage on us-cert.cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.

Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on us-cert.cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.



Organizations observing any suspected malicious activity should follow their established internal procedures and report their findings to CISA for tracking and correlation against other incidents.

No known public exploits specifically target this vulnerability.

• Rockwell Automation