Valmet DNA

1. EXECUTIVE SUMMARY

• CVSS v3 8.8
• ATTENTION: Exploitable from an adjacent network /low attack complexity
• Vendor: Valmet
• Equipment: DNA
• Vulnerability: Inadequate Encryption Strength

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to execute commands remotely with system privileges.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of Valmet DNA, a distributed control system, are affected:

• Valmet DNA: Versions from Collection 2012 to Collection 2021

3.2 VULNERABILITY OVERVIEW

3.2.1    INADEQUATE ENCRYPTION STRENGTH CWE-326

An unauthenticated network user can craft specific packets targeting a Valmet DNA service, listening by default on a specific TCP port. By exploiting a predictable encryption key, the attacker can remotely trigger commands to be executed with system privileges.

CVE-2021-26726 has been assigned to this vulnerability. A CVSS v3 base score of 8.8 has been calculated; the CVSS vector string is (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

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

3.4 RESEARCHER

Ivan Speziale of Nozomi Networks reported this vulnerability to Valmet.

4. MITIGATIONS

Valmet recommends the following:

• Update to the latest version. Contact Valmet customer service to obtain the update.
• Ensure a properly configured firewall is in place to prevent unauthorized access from untrusted networks to the system.

For more information see Valmet's Security Advisory.

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 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 its 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 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 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.

• Valmet