Read the docs
TI-2025-27330 Aliases CVE-2025-40939GHSA-35wm-hq5r-2p36

Improper access control in Siemens SIMATIC CN 4100

Priority LOW 23CWE-284Published · Updated

Key facts

Attack vector
Physical
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-284.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00213 11th percentileScored 2026-11-07
Fix Fixed SIMATIC CN 4100 (Siemens): V4.0.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
SiemensSIMATIC CN 4100before V4.0.1V4.0.1Patch availableCNA
  • SIMATIC CN 4100 VendorSiemens Affected before V4.0.1 Fixed in V4.0.1 Patch available CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:o:siemens:simatic_cn_4100_firmware:*:*:*:*:*:*:*:*before 4.0.1VulnerableSiemens
cpe:2.3:h:siemens:simatic_cn_4100:-:*:*:*:*:*:*:*not specified by NVDRunning onSiemens
  • cpe:2.3:o:siemens:simatic_cn_4100_firmware:*:*:*:*:*:*:*:* Versions before 4.0.1 Vulnerable ·Siemens
  • cpe:2.3:h:siemens:simatic_cn_4100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Siemens

Remediation

  • Fix · CNA SIMATIC CN 4100 (Siemens) Fixed in V4.0.1

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Siemens SIMATIC CN 4100 V4.0.1

    5 records Highest priority Priority MEDIUM 2 MEDIUM, 3 LOW

    Other records, highest priority first

    • TI-2025-27329 Hard-coded credentials in Siemens SIMATIC CN 4100Priority MEDIUM 42
    • TI-2025-27328 Command injection in Siemens SIMATIC CN 4100Priority MEDIUM 40
    • TI-2025-27331 Information disclosure in Siemens SIMATIC CN 4100Priority LOW 31
    Show all 5 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-40939
  2. 2026-10-03 Alias added: GHSA-35wm-hq5r-2p36

References

Advisory 1

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-23989 crypto: algif_aead - Revert to operating out-of-place KEVCVSS 3.1HIGH 7.8
  • TI-2024-21620 A vulnerability has been identified in SIMATIC CN 4100 (All versions < V3.0). CVSS 3.1CRITICAL 10.0
  • TI-2023-27102 A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.7). CVSS 3.1CRITICAL 9.8
  • TI-2024-21619 Hard-coded credentials in Siemens SIMATIC CN 4100 CVSS 3.1CRITICAL 9.8
  • TI-2026-18410 Resource allocation without limits in Siemens SIMATIC CN 4100 CVSS 4.0HIGH 8.7
See all 19 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences