1. EXECUTIVE SUMMARY

CVSS v3 7.8
ATTENTION: Low attack complexity 
Vendor: Siemens  
Equipment: JT Open and JT Utilities 
Vulnerability: Out-of-bounds Read 

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to execute code in the context of the current process. 

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Siemens software is affected: 

JT Open: All versions prior to V11.3.2.0 
JT Utilities: All versions prior to V13.3.0.0 

3.2 VULNERABILITY OVERVIEW

3.2.1 OUT-OF-BOUNDS READ CWE-125 

The affected applications contain an out-of-bounds read vulnerability past the end of an allocated structure while parsing specially crafted JT files. This could allow an attacker to execute code in the context of the current process. 

CVE-2023-29053 has been assigned to this vulnerability. A CVSS v3 base score of 7.8 has been assigned; the CVSS vector string is (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H). 

3.3 BACKGROUND

CRITICAL INFRASTRUCTURE SECTORS: Multiple 
COUNTRIES/AREAS DEPLOYED: Worldwide 
COMPANY HEADQUARTERS LOCATION: Germany 

3.4 RESEARCHER

Michael Heinzl reported this vulnerability to Siemens. 

4. MITIGATIONS

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

Do not open untrusted files using JT Open Toolkit or JT Utilities. 
JT Utilities: Update to V13.3.0.0 or a later version. 
JT Open: Update to V11.3.2.0 or a later version. 

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 the recommendations in the product manuals. 

Additional information regarding Siemens Industrial Security can be found here. 

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

For more information, see the associated Siemens security advisory SSA-642810 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.

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.