Desigo CC ClickOnce Client V6: Improper Control of Generation of Code
CVE-2026-34223 is a high-severity improper control of generation of code vulnerability in Desigo CC ClickOnce Client V6 from Siemens, with a CVSS 3.1 base score of 8.2 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. Affected Desigo CC ClickOnce Client V6 versions: all versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Desigo CC ClickOnce Client V6 you run against the affected versions below, and install the vendor's latest release.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Siemens | Desigo CC ClickOnce Client V6 | all versions | Not stated |
| Siemens | Desigo CC ClickOnce Client V7 | all versions | Not stated |
| Siemens | Desigo CC family V8 | Not specified in the record | Not stated |
| Siemens | Desigo CC family V9 | Not specified in the record | Not stated |
| Siemens | Desigo CC Flex Client V6 | Not specified in the record | Not stated |
| Siemens | Desigo CC Flex Client V7 | Not specified in the record | Not stated |
| Siemens | Desigo CC Installed Client V6 | all versions | Not stated |
| Siemens | Desigo CC Installed Client V7 | all versions | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H. Scored by CNA (siemens.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.6 | High | CNA (siemens.com) |
| CVSS 3.1 | 8.2 | High | CNA (siemens.com) |
Official description
A vulnerability has been identified in Desigo CC ClickOnce Client V6 (All versions), Desigo CC ClickOnce Client V7 (All versions), Desigo CC family V8 (All versions), Desigo CC family V9 (All versions), Desigo CC Flex Client V6 (All versions), Desigo CC Flex Client V7 (All versions), Desigo CC Installed Client V6 (All versions), Desigo CC Installed Client V7 (All versions). 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Improper Control of Generation of Code vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 7.2 High severity
- 8.2 High severity
- 8.8 High severity
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