Siemens Mendix Studio Pro

1. EXECUTIVE SUMMARY

• CVSS v3 5.3
• ATTENTION: Exploitable remotely
• Vendor: Siemens
• Equipment: Mendix Studio Pro
• Vulnerabilities: Incorrect Authorization

2. RISK EVALUATION

Successful exploitation of these vulnerabilities could allow authenticated attackers to manipulate the content of specific objects or to retrieve a specific attribute of arbitrary objects.

3. TECHNICAL DETAILS

3.1 AFFECTED PRODUCTS

Siemens reports these vulnerabilities affect the following Mendix products:

• Mendix Applications using Mendix 8: All versions prior to v8.18.13
• Mendix Applications using Mendix 9: All versions prior to v9.6.2

3.2 VULNERABILITY OVERVIEW

3.2.1    INCORRECT AUTHORIZATION CWE-863

Applications built with affected versions of Mendix Studio Pro do not properly control write access for certain client actions. This could allow authenticated attackers to manipulate the content of specific objects regardless of whether they have write access.

CVE-2021-42025 has been assigned to this vulnerability. A CVSS v3 base score of 5.3 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N).

3.2.2    INCORRECT AUTHORIZATION CWE-863

Applications built with affected versions of Mendix Studio Pro do not properly control read access for certain client actions. This could allow authenticated attackers to retrieve specific attributes of arbitrary objects, regardless of whether they have read access.

CVE-2021-42026 has been assigned to this vulnerability. A CVSS v3 base score of 3.1 has been calculated; the CVSS vector string is (AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N).

3.3 BACKGROUND

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

3.4 RESEARCHER

Siemens reported these vulnerabilities to CISA.

4. MITIGATIONS

Mendix has released updates for the affected product lines and recommends updating to the latest versions and redeploying the applications.

• Mendix Applications using Mendix 8: Update to v8.18.13 or later version and redeploy the application.
• Mendix Applications using Mendix 9: Update to v9.6.2 or v9.7.0 or later version and redeploy the application.

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

• In applications built with affected versions of Mendix Studio Pro, avoid using file documents that contain sensitive information.

As a general security measure, Siemens strongly recommends protecting network access to devices with appropriate mechanisms. In order 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.

For more information about these vulnerabilities, please see Siemens security advisory SSA-779699

CISA recommends users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:

• Ensure the least-privilege user principle is followed.
• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.
• 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 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 have a high attack complexity.