Thales Sentinel LDK Run-Time Environment

1. EXECUTIVE SUMMARY

• CVSS v3 9.6 *ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Thales
• **Equipment:**Thales Sentinel LDK Run-Time Environment (RTE)
• Vulnerability: Incomplete Cleanup

2. RISK EVALUATION

Products that have uninstalled software using the Sentinel LDK Run-Time Environment, may have a port left open that may allow an attacker to connect.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Machines that previously ran and then uninstalled the following versions of Sentinel LDK Run Time Environment are affected:

• Sentinel LDK Run-Time Environment: Versions 7.6 and prior

This RTE is used in products by many different vendors. As new instances are discovered/reported, they will be added to this list of affected products.

3.2 VULNERABILITY OVERVIEW

3.2.1 INCOMPLETE CLEANUP CWE-459

The run-time environment installer adds a firewall rule named “Sentinel License Manager” that allows incoming connections from private networks using TCP Port 1947. While uninstalling, the uninstaller fails to close Port 1947.

CVE-2021-32928 has been assigned to this vulnerability. A CVSS v3 base score of 9.6 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H).

3.3 BACKGROUND

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

3.4 RESEARCHER

This vulnerability was submitted to CISA anonymously.

4. MITIGATIONS

Thales recommends vendors and users to upgrade to RTE Version 8.15 or later.

If uninstalling with affected version, ensure “purge option” is selected. The purge option removes the Sentinel License Manager and closes the port.

If the affected product has been uninstalled:

• Ensure TCP Port 1947 is closed.
• If possible, implement appropriate IDS/IPS measures against TCP Port 1947

For more information on products dependent on the affected RTE see the following vendor security advisories or updates:

• Halliburton GOHFER: Update to Version 9.1.3.57 thru 9.2.x.xx and when uninstalling select the purge option. Upon uninstalling, the purge option removes the Sentinel License Manager and closes the port. Subsequent versions of GOHFER will no longer use Sentinel LDK.

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 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 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.