Siemens Parasolid Installer

​​As of January 10, 2023, CISA will no longer be updating ICS security advisories for Siemens product vulnerabilities beyond the initial advisory. For the most up-to-date information on vulnerabilities in this advisory, please see Siemens' ProductCERT Security Advisories (CERT Services | Services | Siemens Global). 

1. EXECUTIVE SUMMARY

• ​CVSS v3 7.8
• ​ATTENTION: Low attack complexity
• ​Vendor: Siemens
• ​Equipment: Parasolid
• ​Vulnerability: Incorrect Permission Assignment for Critical Resource

2. RISK EVALUATION

​Successful exploitation of this vulnerability could allow an attacker to misuse the vulnerability and escalate privileges.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

​The following products from Siemens are affected if installed with Parasolid installer:

• ​Parasolid V35.0: All versions
• ​Parasolid V35.1: All versions

3.2 VULNERABILITY OVERVIEW

3.2.1 INCORRECT PERMISSION ASSIGNMENT FOR CRITICAL RESOURCE CWE-732

​Nullsoft Scriptable Install System (NSIS) before v3.09 creates an "uninstall directory" with insufficient access control. This could allow an attacker to misuse the vulnerability and escalate privileges.

​CVE-2023-37378 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: Multiple Sectors
• ​COUNTRIES/AREAS DEPLOYED: Worldwide
• ​COMPANY HEADQUARTERS LOCATION: Germany

3.4 RESEARCHER

​Siemens reported this vulnerability to CISA.

4. MITIGATIONS

Only systems on which Parasolid is installed with a Parasolid installer is impacted. Siemens recommends uninstalling impacted Parasolid instances and reinstalling with the latest available installer:

• ​Parasolid v35.0: Latest installer.
• ​Parasolid v35.1: Latest installer.

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

• ​Scan each computer on which Parasolid has ever been installed with an up-to-date anti-virus program and follow its recommendations.
• ​Ensure only trusted persons have access to the system and avoid the configuration of additional accounts.

​As a general security measure, Siemens recommends protecting network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends configuring the environment according to Siemens' operational guidelines for industrial security and following product manual recommendations.

​Additional information on Siemens industrial security can be found on the Siemens industrial security webpage.

​For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT.

​For more information see the associated Siemens security advisory SSA-116172 in HTML and CSAF.

​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 business networks.
• ​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 at cisa.gov/ics. Several CISA products detailing cyber defense best 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 at cisa.gov/ics in the technical information paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.

​Organizations observing suspected malicious activity should follow established internal procedures and report findings to CISA for tracking and correlation against other incidents.

​No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely.

• Siemens