Siemens TIA Project-Server formerly known as TIA Multiuser Server

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 6.7
• ATTENTION: High attack complexity  
• Vendor: Siemens  
• Equipment: TIA Project-Server 
• Vulnerability: Untrusted Search Path 

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to escalate privileges when tricking a legitimate user to start the service from an attacker-controlled path. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following software from Siemens is affected: 

• TIA Multiuser Server V14: All versions 
• TIA Multiuser Server V15: All versions prior to V15.1 Update 8 
• TIA Project-Server: All versions prior to V1.1 
• TIA Project-Server V16: All versions 
• TIA Project-Server V17: All versions   

3.2 VULNERABILITY OVERVIEW

3.2.1 UNTRUSTED SEARCH PATH CWE-426 

Affected applications contain an untrusted search path vulnerability that could allow an attacker to escalate privileges when tricking a legitimate user to start the service from an attacker-controlled path. 

CVE-2022-35868 has been assigned to this vulnerability. A CVSS v3 base score of 6.7 has been assigned. The CVSS vector string is (CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H). 

3.3 BACKGROUND

• CRITICAL INFRASTRUCTURE SECTORS: Critical Manufacturing 
• COUNTRIES/AREAS DEPLOYED: Worldwide 
• COMPANY HEADQUARTERS LOCATION: Germany 

3.4 RESEARCHER

Siemens reported this vulnerability to CISA. 

4. MITIGATIONS

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

• TIA Project-Server: Update to V1.1 or later version 
• TIA Multiuser Server V15: Update to V15.1 Update 8 or a later version. Migrate to TIA Project-Server V1.1 or a later version. 
• TIA Project-Server V16: Currently no fix is available. Migrate to TIA Project-Server V1.1 or a later version. 
• TIA Project-Server V17: Currently no fix is available. Migrate to TIA Project-Server V1.1 or a later version. 
• TIA Multiuser Server V14: Currently no fix is planned. Migrate to TIA Project-Server V1.1 or a later version. 
• Ensure the directory set as working directory when starting the TIA Project-Server or TIA Multiuser Server does not contain untrusted files. 

As a general security measure, Siemens strongly recommends users protect network access to devices with appropriate mechanisms. To operate the devices in a protected IT environment, Siemens recommends to configure the environment according to Siemens' operational guidelines for Industrial Security and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at the Siemens Industrial Security website.  

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

For more information, see the associated Siemens security advisory SSA-640968 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.

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

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

• Do not click web links or open attachments in unsolicited email messages. 
• Refer to Recognizing and Avoiding Email Scams for more information on avoiding email scams. 
• Refer to Avoiding Social Engineering and Phishing Attacks for more information on social engineering attacks. 

No known public exploits specifically target this vulnerability. This vulnerability is not exploitable remotely. This vulnerability has a high attack complexity.