CVE-2025-40939
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Physical
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2025-40939- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 4.6 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2025-201917
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.
- Record
EUVD-2025-201917- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-35wm-hq5r-2p36
A vulnerability has been identified in SIMATIC CN 4100 (All versions < V4.0.1). The affected...
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.
- Record
GHSA-35wm-hq5r-2p36- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.6 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-40939- CVSS 4.0
- 5.1 Medium
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.6 Medium
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-40939 is a medium vulnerability (CVSS 5.1) in Siemens Simatic Cn 4100, published December 9, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. No source names a fixed version.