CVE-2023-29131

CRITICAL

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5). Affected device consists of an incorrect default value in the SSH configuration. This could allow an attacker to bypass...

Affects 1 product across 2 vendors.

BCS6.65
CVSS 3.110.0
EPSS0.4%
Percentile35th
PatchUnknown
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, no authentication required, no user interaction needed, can impact systems beyond the vulnerable component, full confidentiality impact, full integrity impact, full availability impact.
CWE Weakness Definitions
CWE-276: Incorrect Default Permissions

Software sets overly permissive default access rights during installation or resource creation.

Related Attack Patterns (CAPEC)
CAPEC-81 Web Server Logs Tampering
via CWE-276
CAPEC-127 Directory Indexing
via CWE-276
CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs
via CWE-276

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ SAGE Intelligence — CITED Relevance Research Team

A critical vulnerability has been identified in all versions of SIMATIC CN 4100 prior to V2.5, which involves an incorrect default value in the SSH configuration. This can potentially allow attackers to bypass network isolation, leading to severe impacts on confidentiality, integrity, and availability.

BSID: BS-2023-GLOBAL-350284-C • Model: Qwen/Qwen2.5-72B-Instruct-AWQ • Confidence: HIGH

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Frequently Asked Questions
What is CVE-2023-29131?
A critical vulnerability has been identified in all versions of SIMATIC CN 4100 prior to V2.5, which involves an incorrect default value in the SSH configuration. This can potentially allow attackers to bypass network isolation, leading to severe impacts on confidentiality, integrity, and availability.
What is the CVSS score for CVE-2023-29131?
CVE-2023-29131 has CVSS 10.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. EPSS: 0.4%.
Is CVE-2023-29131 actively exploited?
No confirmed active exploitation of CVE-2023-29131 as of 2026-05-30.
How do I remediate CVE-2023-29131?
Priority: IMMEDIATE.
What systems are affected by CVE-2023-29131?
CVE-2023-29131 affects: Fujitsu-Siemens, Siemens.
What NERC-CIP standard applies to CVE-2023-29131?
NERC CIP CIP-007 CIP-007-R2: This CVE violates CIP-007-R2 as it allows unauthorized access to the control system, compromising the security of the electronic security perimeter.
What IEC 62443 requirement maps to CVE-2023-29131?
IEC 62443 SR 7.6: This CVE maps to SR 7.6 because it involves a misconfiguration that can be exploited to bypass network isolation, which is a critical security control in IEC 62443.
Vulnerability Details
CVE IDCVE-2023-29131
BSIDBS-2023-GLOBAL-350284-C BreachSpider Global ID
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Published2023-07-11
Last Modified2026-02-18
ICS Relevance80%
Weakness (CWE)
Verticals
ICS-OT
SourceNVD
Official Description

A vulnerability has been identified in SIMATIC CN 4100 (All versions < V2.5). Affected device consists of an incorrect default value in the SSH configuration. This could allow an attacker to bypass network isolation.

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

The vulnerability can be exploited remotely without authentication, requiring low skill level. An attacker can leverage the incorrect default value in the SSH configuration to bypass network isolation mechanisms, gaining unauthorized access to the affected device and potentially the entire network.

Exploitation Likelihood: MEDIUM

Affected Products
VendorProductFixed Version
Fujitsu-Siemens &mdash;
Siemens Simatic Cn 4100 Firmware
Remediation

No patch URL on record. Monitor vendor security advisories directly.

Threat Intelligence
● Threat Intelligence Validated: July 2026 | Threat Age: 1110 Days
CISA KEVNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
● Virtual Patch — CITED Relevance SAGE Engine MEDIUM CONFIDENCE

Implement strict network segmentation and monitor SSH traffic for unusual activity. Ensure that only authorized users have access to the affected devices.

No reliable network detection signature exists for this vulnerability class — apply the compensating controls above and the vendor patch. SAGE only publishes a network rule when a concrete on-the-wire signature can be grounded in the advisory.

NERC CIP: CIP-007 CIP-007-R2
This CVE violates CIP-007-R2 as it allows unauthorized access to the control system, compromising the security of the electronic security perimeter.
IEC 62443: SR 7.6
This CVE maps to SR 7.6 because it involves a misconfiguration that can be exploited to bypass network isolation, which is a critical security control in IEC 62443.

Virtual patch generated by CITED Relevance SAGE. Validate in isolated environment before production deployment. Compensating control only - does not replace vendor patch.

SAGE Enrichment Record — provenance & audit hash
ModelQwen/Qwen2.5-72B-Instruct-AWQ
ConfidenceHIGH
Enriched At2026-05-24
SHA-512 Audit Hash5a8daf5e0b7115ed08c5aec7082962595a956c8a03db1fc33419340220f46e3818394617eb862f1726a07abdb2d49a22ddc58fd88d76dffeb49f8d00e4e74ae6
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