Siemens Mendix Excel Importer

1. EXECUTIVE SUMMARY

• CVSS v3 6.5
• ATTENTION: Exploitable remotely/low attack complexity
• Vendor: Siemens
• Equipment: Mendix Excel Importer Module
• Vulnerability: XML Entity Expansion

2. RISK EVALUATION

Successful exploitation of this vulnerability could allow an attacker to compromise the availability of the affected component.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

The following Siemens products are affected:

• Mendix Excel Importer Module (Mendix 8 compatible): All versions prior to v9.2.2
• Mendix Excel Importer Module (Mendix 9 compatible): All versions prior to v10.1.2

3.2 VULNERABILITY OVERVIEW

3.2.1    IMPROPER RESTRICTION OF RECURSIVE ENTITY REFERENCES IN DTDS (‘XML ENTITY EXPANSION’) CWE-776

The affected component is vulnerable to XML entity expansion injection. An attacker may use this to compromise the availability of the affected component.

CVE-2022-34467 has been assigned to this vulnerability. A CVSS v3 base score of 6.5 has been calculated; the CVSS vector string is (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/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

Siemens recommends updating to the latest version:

• Mendix Excel Importer Module (Mendix 8 compatible): Update to v9.2.2 or later.
• Mendix Excel Importer Module (Mendix 9 compatible): Update to v10.1.2 or later.

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 users configure the environment according to the Siemens operational guidelines for industrial security and follow the recommendations in the product manuals.

For additional information, please refer to Siemens Security Advisory SSA-610768

CISA recommends users take defensive measures to minimize the risk of exploitation of this vulnerability these vulnerabilities. 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.