CVE-2021-22681: Rockwell Multiple Products Insufficient Protected Credentials Vulnerability

This vulnerability affects multiple Rockwell Automation products and centers on insufficient protection of credentials. In the Studio 5000 Logix Designer software, a key used to verify communication between the design software and Logix controllers can be discovered. An attacker who obtains the key and has network access to a controller could connect an unauthorized application to it. The issue is relevant for organizations running industrial control systems, where controller access can affect process integrity and safety.

How it works

The weakness is classified as CWE-522, insufficiently protected credentials. The software stores or handles the verification key in a manner that permits discovery by an unauthorized party. Once obtained, the key allows an application to present itself as legitimate design software and establish a connection to a Logix controller.

• Exploitation requires prior network access to the target controller.
• No specific exploit mechanics or code are described in the available information.

Am I affected? How to find it in your systems

Confirm whether any Rockwell Automation products, particularly Studio 5000 Logix Designer and associated Logix controllers, are present in the environment. Inventory should cover engineering workstations, HMI servers, and any systems that communicate directly with Logix controllers. Because exact affected versions are not listed here, compare installed software against the vendor advisory.

• Look for network traffic involving controller discovery or authentication that originates from unexpected hosts.
• Review logs on engineering stations for key-handling operations or unexpected connection attempts to controllers.
• Map network segments that allow direct access from non-engineering systems to Logix controllers.

How to remediate

Apply mitigations or updates according to the vendor instructions referenced in the advisory. Where cloud services are involved, follow applicable BOD 22-01 guidance. If no effective mitigation is available, discontinue use of the affected product.

• Restrict network access so that only authorized engineering workstations can reach Logix controllers.
• Implement allow-listing of source addresses or certificates for controller communication where supported.

If you can't patch immediately

Until a fix can be applied, reduce exposure by isolating controller networks from general-purpose systems. Monitor for anomalous connection attempts to Logix controllers and alert on traffic that bypasses expected engineering workstations. Consider disabling remote or unauthenticated design-software connections if the operational process permits.

• Segment controller networks using firewalls or VLANs that enforce strict source restrictions.
• Enable logging of all controller connection events and review them regularly for unauthorized sources.

If your data may have been exposed

Actively exploited vulnerabilities of this type can lead to unauthorized access and subsequent breaches. Organizations can run a free exposure scan of their email addresses against known breach data to check for prior incidents.