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Missing AuthenticationWeakness · CWE-306

CVE-2025-40817

MEDIUM · 6.5 CVSS v3.1 Published 2025-11-11
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability has been identified in LOGO! 12/24RCE (6ED1052-1MD08-0BA2) (All versions), LOGO! 12/24RCEo (6ED1052-2MD08-0BA2) (All versions), LOGO! 230RCE (6ED1052-1FB08-0BA2) (All versions), LOGO! 230RCEo (6ED1052-2FB08-0BA2) (All versions), LOGO! 24CE (6ED1052-1CC08-0BA2) (All versions), LOGO! 24CEo (6ED1052-2CC08-0BA2) (All versions), LOGO! 24RCE (6ED1052-1HB08-0BA2) (All versions), LOGO! 24RCEo (6ED1052-2HB08-0BA2) (All versions), SIPLUS LOGO! 12/24RCE (6AG1052-1MD08-7BA2) (All versions), SIPLUS LOGO! 12/24RCEo (6AG1052-2MD08-7BA2) (All versions), SIPLUS LOGO! 230RCE (6AG1052-1FB08-7BA2) (All versions), SIPLUS LOGO! 230RCEo (6AG1052-2FB08-7BA2) (All versions), SIPLUS LOGO! 24CE (6AG1052-1CC08-7BA2) (All versions), SIPLUS LOGO! 24CEo (6AG1052-2CC08-7BA2) (All versions), SIPLUS LOGO! 24RCE (6AG1052-1HB08-7BA2) (All versions), SIPLUS LOGO! 24RCEo (6AG1052-2HB08-7BA2) (All versions). Affected devices do not conduct certain validations when interacting with them. This could allow an unauthenticated remote attacker to change time of the device, which means the device could behave differently.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The vulnerability allows an unauthenticated remote attacker to change the system time on affected Siemens LOGO! PLC devices by sending specially crafted requests without proper validation. Since LOGO! devices rely on time-based logic for control operations, manipulating the device clock could cause the PLC to execute logic at incorrect times, potentially leading to unexpected industrial process behavior.

MitigationImplement network segmentation to restrict unauthorized access to the PLC network, and configure firewall rules to block external time manipulation requests. Monitor for unexpected time changes and consider applying vendor-provided compensating controls once available.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Siemens LOGO! PLC device
    Locate and confirm the device model by accessing the PLC directly via the LOGO! Comfort software, checking the device label, or querying the device's web interface if available. Confirm it is a Siemens LOGO! series PLC.
    Affected if The target device is a Siemens LOGO! PLC (any model in the LOGO! 0BA7, 0BA8, or newer series).
  2. Determine device firmware version
    Connect to the LOGO! device via LOGO! Comfort software and navigate to the device information section, or access the web interface and check the firmware/software version displayed. Record this version number.
    Affected if The installed firmware version falls within the affected version range published by Siemens for this CVE (if known); otherwise, all unpatched LOGO! versions are potentially affected.
  3. Verify network exposure
    Review network architecture and firewall rules to determine if the LOGO! PLC is directly accessible from untrusted networks or the internet. Use network scanning tools (e.g., nmap) to check if ports used by LOGO! (typically port 10000/TCP for web server, port 10001/TCP for programming) are exposed externally.
    Affected if The LOGO! device management ports are accessible from untrusted networks without authentication barriers.
  4. Check for time synchronization configuration
    Access the LOGO! Comfort software, go to the device settings, and check if NTP time synchronization is configured. Also check if the device has any explicit time change protection or authentication enabled for time-related commands.
    Affected if The device lacks proper authentication or validation for time change commands and allows unauthenticated time modifications.
  5. Review logs for unauthorized time changes
    If the LOGO! device or associated network logs are available, search for any timestamps or log entries indicating unexpected or unauthorized time modifications, particularly from external IP addresses.
    Affected if Logs show time change events that were not initiated by authorized administrators.

A user is affected if they have an unpatched Siemens LOGO! PLC device exposed to untrusted network access where unauthenticated attackers can send time change requests.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement network segmentation to restrict unauthorized access to the PLC network, and configure firewall rules to block external time manipulation requests. Monitor for unexpected time changes and consider applying vendor-provided compensating controls once available.

Have this fixed Scoped from the published advisory
  • Consultation8.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,380
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-40817 in production — separate from our analysis above.

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What this is

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What belongs here
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