SIMATIC CN 4100: Improper Neutralization of Special Elements used in a Command
CVE-2025-40937 is a high-severity improper neutralization of special elements used in a command vulnerability in SIMATIC CN 4100 from Siemens, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version V4.0.1 as the first without the flaw, so updating SIMATIC CN 4100 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update SIMATIC CN 4100 to V4.0.1 or a later version.
- Update Simatic Cn 4100 Firmware to 4.0.1 or a later version.
- Read the advisory on cert-portal.siemens.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Siemens | SIMATIC CN 4100 | before V4.0.1 | V4.0.1 |
| Siemens | Simatic Cn 4100 Firmware | before 4.0.1 | 4.0.1 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (siemens.com) |
| CVSS 3.1 | 8.3 | High | CNA (siemens.com) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected application do not properly validate input parameters in its REST API, resulting in improper handling of unexpected arguments. This could allow an authenticated attacker to execute arbitrary code with limited privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
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 vulnerabilities in SIMATIC CN 4100
- 7.5 High severity
- 9.1 Critical severity
- 7.8 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.2 High severity
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
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