CVE-2025-40940Network attack vector

Sensitive-data exposure via inconsistent SNMP behavior

Published Dec 9, 2025 · Updated Dec 9, 2025

Information exposure in Siemens SIMATIC CN 4100 before 4.0.1 allows remote authenticated users to read sensitive data through SNMP. The SNMP service behaves inconsistently across protocol versions, unexpectedly remaining available and handling configuration unreliably. Administrative privileges and network access are required; the disclosed data affects confidentiality without reported modification or interruption.

CVSS severity6.9
Medium
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information exposure in Siemens SIMATIC CN 4100 before 4.0.1 allows remote authenticated users to read sensitive data through SNMP. The SNMP service behaves inconsistently across protocol versions, unexpectedly remaining available and handling configuration unreliably. Administrative privileges and network access are required; the disclosed data affects confidentiality without reported modification or interruption.

The record

CVE
CVE-2025-40940
Published
Dec 9, 2025
Updated
Dec 9, 2025
Vendor
Siemens
Product
SIMATIC CN 4100
Classifications
CWE-200
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <V4.0.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Siemens · SIMATIC CN 4100version=0 <V4.0.1

Published CVSS scores

6.9Siemens AGCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
4.9Siemens AGCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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