1. EXECUTIVE SUMMARY

  • CVSS v3 5.3
  • ATTENTION: Exploitable remotely/low attack complexity
  • Vendor: Siemens
  • Equipment: Nucleus
  • Vulnerability: Use of Insufficiently Random Values

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow a local attacker to take over the system where the software is installed.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports that these vulnerabilities affect the following LOGO! engineering software products:

  • LOGO! Soft Comfort: All versions

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER LIMITATION OF A PATHNAME TO A RESTRICTED DIRECTORY (‘PATH TRAVERSAL’) CWE-22

A vulnerability could be triggered while importing a compromised project file to the affected software, which may allow the execution of commands on the system.

CVE-2020-25243 has been assigned to this vulnerability. A CVSS v3 base score of 5.1 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L).

3.2.2    UNCONTROLLED SEARCH PATH ELEMENT CWE-427

The software insecurely loads libraries that may allow an attacker to use DLL hijacking and takeover the system where the software is installed. 

CVE-2020-25244 has been assigned to this vulnerability. A CVSS v3 base score of 8.4 has been calculated; the CVSS vector string is (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

3.3 BACKGROUND

  • CRITICAL INFRASTRUCTURE SECTORS: Commercial Facilities, Transportation Systems
  • COUNTRIES/AREAS DEPLOYED: Worldwide
  • COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

Mashav Sapir from Claroty reported these vulnerabilities to Siemens.

4. MITIGATIONS

Siemens has identified the following specific workarounds and mitigations that users can apply to reduce the risk:

  • If possible do not execute the LOGO! Soft Comfort software with administrative privileges
  • Restrict access to project files on the engineering station to trusted users
  • Import only project files from trusted sources

Please see Siemens Security Advisory SSA-983300 for more information.

CISA also recommends users take the following measures to protect themselves from social engineering attacks: 

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 these vulnerabilities. These vulnerabilities are not exploitable remotely.

Source:

https://us-cert.cisa.gov/ics/advisories/icsa-21-103-09