1. EXECUTIVE SUMMARY

  • CVSS v3 7.8
  • ATTENTION: Low skill level to exploit
  • Vendor: Emerson
  • Equipment: ValveLink
  • Vulnerability: Improper Access Control

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow arbitrary code execution.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following versions of ValveLink digital valve controller software are affected:

  • ValveLink, v12.0.264 to v13.4.118

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER ACCESS CONTROL CWE-284

A vulnerability in the ValveLink software may allow a local, unprivileged, trusted insider to escalate privileges due to insecure configuration parameters.

CVE-2020-6971 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Chemical, Critical Manufacturing, Dams, Energy, Food and Agriculture, Healthcare and Public Health, Nuclear Reactors, Materials and Waste, Transportation Systems, Water
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: United States

3.4 RESEARCHER

Emerson Cybersecurity reported this vulnerability to CISA.

4. MITIGATIONS

Emerson recommends users upgrade the affected products listed below:

ValveLink, v12.0.264 to v13.4.118: Apply upgrade for ValveLink v13.4.123 or higher.

Software upgrades are available to users by contacting an Emerson Impact Partner. AMS, Ovation, and DeltaV users with ValveLink can download the update through the Guardian Support Portal.

To limit exposure to this vulnerability, Emerson recommends immediately deploying and configuring the latest version of ValveLink as described in the ValveLink installation guide.

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

  • Practice principle of least privilege.
  • 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 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.

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.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.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. This vulnerability is not exploitable remotely.

Source:

https://www.us-cert.gov/ics/advisories/icsa-20-063-01