EXECUTIVE SUMMARY

  • CVSS v3 10.0
  • ATTENTION: Exploitable remotely/low skill level to exploit
  • Vendor: SWARCO TRAFFIC SYSTEMS
  • Equipment: CPU LS4000
  • Vulnerability: Improper Access Control

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow access to the device and disturb operations with connected devices.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

CERT VDE reports the vulnerability affects the following traffic light controller:

  • CPU LS4000: All OS versions starting with G4

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER ACCESS CONTROL CWE-284

An open port used for debugging grants root access to the device without access control via network.

CVE-2020-12493 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).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Transportation Systems
  • COUNTRIES/AREAS DEPLOYED: Europe
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Martin Aman (ProtectEM) reported this vulnerability in coordination with CERT@VDE

4. MITIGATIONS

SWARCO TRAFFIC SYSTEMS released a patch to fix the vulnerability and close the port. Please contact SWARCO TRAFFIC SYSTEMS for further information.

CERT@VDE published VDE-2020-016 regarding this vulnerability.

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 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.

Source:

https://www.us-cert.gov/ics/advisories/icsa-20-154-06