Siemens SIMATIC CN 4100 up to 4.0.0 USB Port access control

CVSS Meta Temp Score
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CTI Interest Score
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4.5$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Siemens SIMATIC CN 4100 up to 4.0.0. This issue affects some unknown processing of the component USB Port. The manipulation results in access control. This vulnerability is known as CVE-2025-40939. An attack on the physical device is feasible. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Siemens SIMATIC CN 4100 up to 4.0.0. It has been classified as critical. Affected is an unknown code block of the component USB Port. The manipulation with an unknown input leads to a access control vulnerability. CWE is classifying the issue as CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. This is going to have an impact on availability. CVE summarizes:

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected device contains a USB port which allows unauthenticated connections. This could allow an attacker with physical access to the device to trigger reboot that could cause denial of service condition.

The advisory is available at cert-portal.siemens.com. This vulnerability is traded as CVE-2025-40939 since 04/16/2025. The exploitability is told to be easy. Local access is required to approach this attack. The exploitation doesn't require any form of authentication. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

Upgrading to version 4.0.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-201917). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.5

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 4.6
CNA Vector (siemens): 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Access control
CWE: CWE-284 / CWE-266
CAPEC: 🔒
ATT&CK: 🔒

Physical: Yes
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: SIMATIC CN 4100 4.0.1

Timelineinfo

04/16/2025 CVE reserved
12/09/2025 +237 days Advisory disclosed
12/09/2025 +0 days VulDB entry created
12/09/2025 +0 days VulDB entry last update

Sourcesinfo

Vendor: siemens.com

Advisory: ssa-416652
Status: Confirmed

CVE: CVE-2025-40939 (🔒)
GCVE (CVE): GCVE-0-2025-40939
GCVE (VulDB): GCVE-100-335130
EUVD: 🔒

Entryinfo

Created: 12/09/2025 12:14
Updated: 12/09/2025 15:39
Changes: 12/09/2025 12:14 (78), 12/09/2025 15:39 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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