Security readout for executives and security teams
Plain-English summary
Siemens SIMATIC CN 4100 devices before V2.5 may ship with an unsafe SSH default configuration. A logged-in network attacker could use this to bypass intended network isolation, creating risk across segmented industrial environments.
Executive priority
Treat as high priority for industrial environments using SIMATIC CN 4100, especially where segmentation is a key safety or operational control. Plan remediation through normal OT change windows, but do not defer inventory and exposure reduction.
Technical view
CVE-2023-29131 is a CWE-276 incorrect default permission/configuration issue in SIMATIC CN 4100 versions below V2.5. The CVSS 3.1 score is 7.4, with network access, low complexity, low privileges, no user interaction, and changed scope.
Likely exposure
Exposure is limited to Siemens SIMATIC CN 4100 deployments running versions earlier than V2.5. Risk is highest where SSH management access is reachable from broader networks or lower-trust operator/admin segments.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The CVSS temporal vector includes proof-of-concept exploit maturity, but no exploit procedure or real-world campaign evidence is provided.
Researcher notes
The available evidence identifies the root cause only at a high level: an incorrect SSH default value enabling network isolation bypass. The bundle does not include detailed configuration names, exploit steps, or telemetry indicators.
Mitigation direction
- Inventory SIMATIC CN 4100 devices and identify any versions below V2.5.
- Upgrade affected devices to V2.5 or later after confirming Siemens guidance.
- Review Siemens SSA-313488 for product-specific remediation and operational constraints.
- Restrict SSH management access to trusted administrative networks only.
- Verify network segmentation still blocks unintended management-plane paths.
Validation and detection
- Confirm deployed SIMATIC CN 4100 firmware/software version against the affected range.
- Review SSH configuration defaults against Siemens advisory guidance.
- Check firewall and segmentation rules around CN 4100 management interfaces.
- Look for unexpected SSH access paths from lower-trust network zones.
- Document compensating controls where upgrade timing depends on maintenance windows.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-276: Exact CWE lookup
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Open ATT&CK lookupCVE-2023-29131 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:P/RL:O/RC:C
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:P/RL:O/RC:C3.13.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L/E:P/RL:O/RC:C
Source materials
- CVE List V5 sourceCVE List V5
- https://cert-portal.siemens.com/productcert/pdf/ssa-313488.pdfCVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Default Permissions
Incorrect Default Permissions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.