Siemens Desigo CC family
Siemens Desigo CC graphics documents can run attacker scripts and compromise client operating systems.
CISA republished Siemens SSA-330084 covering CVE-2026-34223, a client code-execution flaw in the Desigo CC building-management family. Scripts embedded in user-defined graphics are not sufficiently validated and run when a privileged user opens a crafted document, allowing arbitrary file writes on the client. CVSS 3.1 is 8.2, with local access and user interaction required. All Desigo CC V6 and V7 versions are listed as affected. Michelin CERT reported the issue; no exploitation is stated.
- CVE-2026-34223 is client code injection scored CVSS 8.2.
- Crafted graphics documents execute scripts when a privileged user opens them.
- Attackers can write arbitrary files and compromise the client operating system.
- Every Desigo CC family V6 and V7 release is listed as affected.
Vulnerabilities mentionedAll →
- CVE-2026-342238.6<1%Client Code Execution via malicious graphics documents in Siemens Desigo CCpublished · Siemens Desigo CC ClickOnce Client
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2026-34223 | Client Code Execution via malicious graphics documents in Siemens Desigo CC Siemens Desigo CC client applications (ClickOnce, Flex, and Installed Client variants) insufficiently validate scripts embedded in user-defined graphics documents, enabling script injection (CWE-94). To trigger it, an attacker must craft a graphics document containing malicious script commands and entice a user with sufficient privileges to open it in the client application; the embedded script then executes within that client instance. Successful exploitation allows the attacker to write arbitrary files to the client's operating system, which can lead to full compromise of the client workstation and lateral movement within the organization's network. All client variants and versions listed (V6 through V9) are affected, so operators and engineers running Desigo CC building-management clients are in scope. Exploitation has not been observed: there is no public proof-of-concept, the flaw is not in CISA's KEV catalog, and EPSS assigns a roughly 0.1% probability of exploitation within 30 days (3rd percentile). |
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Summary
A Client Code Execution (CCE) vulnerability has been identified in Desigo CC, potentially allowing malicious actors to execute arbitrary code on client devices through specially crafted graphics documents. This vulnerability leverages user-defined graphics containing embedded scripts that are executed on client application instances. Successful exploitation could lead to compromise of the client operating system and potential lateral movement within the organization.
The following versions of Siemens Desigo CC family are affected:
- Desigo CC family V6 vers:all/* (CVE-2026-34223)
- Desigo CC family V7 vers:all/* (CVE-2026-34223)
| CVSS | Vendor | Equipment | Vulnerabilities |
|---|---|---|---|
| v3 8.2 | Siemens | Siemens Desigo CC family | Improper Control of Generation of Code ('Code Injection') |
Background
- Critical Infrastructure Sectors: Critical Manufacturing, Commercial Facilities
- Countries/Areas Deployed: Worldwide
- Company Headquarters Location: Germany
Vulnerabilities
CVE-2026-34223
The affected application is vulnerable to Client Code Execution (CCE) due to insufficient input validation when handling scripts embedded within user-defined graphics documents. Specifically, when the script within a graphics document is designed or modified by an attacker to include malicious commands. When a user opens a compromised graphics document, the embedded script is executed on the client application instance, allowing an attacker to write arbitrary files to the client's operating system. Successful exploitation requires an attacker to craft a malicious graphics document and entice a user with sufficient privileges to display it. This could lead to compromise of the client operating system and potential lateral movement within the organization.
Affected Products
Siemens Desigo CC family
Vendor:
Siemens
Product Version:
Desigo CC family V6, Desigo CC family V7
Product Status:
known_affected
Relevant CWE: CWE-94 Improper Control of Generation of Code ('Code Injection')
Metrics
| CVSS Version | Base Score | Base Severity | Vector String |
|---|---|---|---|
| 3.1 | 8.2 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H |
Acknowledgments
- Michelin CERT reported this vulnerability to Siemens.
General Recommendations
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 (Download: https://www.siemens.com/cert/operational-guidelines-industrial-security), and to follow the recommendations in the product manuals. Additional information on Industrial Security by Siemens can be found at: https://www.siemens.com/industrialsecurity
Additional Resources
For further inquiries on security vulnerabilities in Siemens products and solutions, please contact the Siemens ProductCERT: https://www.siemens.com/cert/advisories
Terms of Use
The use of Siemens Security Advisories is subject to the terms and conditions listed on: https://www.siemens.com/productcert/terms-of-use.
Legal Notice and Terms of Use
This product is provided subject to this Notification (https://www.cisa.gov/notification) and this Privacy & Use policy (https://www.cisa.gov/privacy-policy).
Recommended Practices
CISA recommends users take defensive measures to minimize the exploitation risk of these vulnerabilities.
- 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 more secure methods, such as Virtual Private Networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most recent 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 cisa.gov. 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.
CISA encourages organizations to implement recommended cybersecurity strategies for proactive defense of ICS assets. Additional mitigation guidance and recommended practices are publicly available on the ICS webpage at cisa.gov 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.
Advisory Conversion Disclaimer
This ICSA is a verbatim republication of Siemens ProductCERT SSA-330084 from a direct conversion of the vendor's Common Security Advisory Framework (CSAF) advisory. This is republished to CISA's website as a means of increasing visibility and is provided "as-is" for informational purposes only. CISA is not responsible for the editorial or technical accuracy of republished advisories and provides no warranties of any kind regarding any information contained within this advisory. Further, CISA does not endorse any commercial product or service. Please contact Siemens ProductCERT directly for any questions regarding this advisory.
Revision History
- Initial Release Date: 2026-09-08
| Date | Revision | Summary |
|---|---|---|
| 2026-09-08 | 1 | Publication Date |
| 2026-09-22 | 2 | Initial CISA Republication of Siemens ProductCERT SSA-330084 advisory |