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Pfc 200 FirmwareOperating system · Wago

CVE-2019-5078

CRITICAL · 9.1 CVSS v3.1 Published 2019-12-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable 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
An exploitable denial of service vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a denial of service, resulting in the device entering an error state where it ceases all network communications. An attacker can send unauthenticated packets to trigger this vulnerability.

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

A denial of service vulnerability exists in the iocheckd service 'I/O-Check' functionality of WAGO PFC200 (firmware 03.01.07(13) and 03.00.39(12)) and PFC100 (firmware 03.00.39(12)) programmable logic controllers. An unauthenticated attacker can send specially crafted packets to trigger this vulnerability, causing the device to enter an error state and cease all network communications.

MitigationApply vendor firmware updates when available and implement network segmentation to restrict unauthorized access to the iocheckd service. Consider deploying intrusion detection to identify anomalous packets targeting this service.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Pfc 200 FirmwareOperating system
Affected:= 03.00.39\(12\)= 03.01.07\(13\)
Pfc 100 FirmwareOperating system
Affected:= 03.00.39\(12\)

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
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

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

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 device model
    Check the device label, Web UI, or system information to confirm whether the device is a WAGO PFC200 or PFC100 programmable logic controller.
    Affected if The device is NOT a WAGO PFC200 or PFC100, then it is not affected by this CVE.
  2. Check firmware version
    Access the device's web interface, console, or use the WAGO management tools to retrieve the current firmware version. Compare against the affected versions 03.00.39(12) and 03.01.07(13).
    Affected if The installed firmware version matches exactly 03.00.39(12) or 03.01.07(13), then the device is potentially affected.
  3. Verify iocheckd service status
    Access the device's command line or administrative interface and check whether the iocheckd service (I/O-Check service) is enabled and running.
    Affected if The iocheckd service is enabled and accessible on the network, then the denial of service condition can be triggered.
  4. Assess network exposure
    Review network configuration, firewall rules, and access control lists to determine if the iocheckd service port is exposed to untrusted or unauthenticated network segments.
    Affected if The iocheckd service is reachable by unauthenticated attackers on the network, then the vulnerability can be exploited.

A user is affected if they have a WAGO PFC200 (firmware 03.00.39(12) or 03.01.07(13)) or PFC100 (firmware 03.00.39(12)) with the iocheckd service exposed to unauthenticated network access.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware updates when available and implement network segmentation to restrict unauthorized access to the iocheckd service. Consider deploying intrusion detection to identify anomalous packets targeting this service.

Recommended fix Moderate confidence

Latest available PFC100/PFC200 firmware from WAGO (contact WAGO support for specific version containing the CVE-2019-5078 fix)

  1. 1. Identify the current firmware version of the WAGO PFC100 or PFC200 device by accessing the device's web interface or using WAGO's admin tools.
  2. 2. Navigate to the official WAGO download portal (wago.com) and locate the firmware download section for PFC100 and PFC200 series devices.
  3. 3. Download the latest available firmware version for your specific device model. WAGO typically releases firmware updates that address security vulnerabilities including CVE-2019-5078.
  4. 4. Follow WAGO's official firmware upgrade procedure documented in the device manual - this usually involves accessing the device via web browser or using WAGO's programming software.
  5. 5. After upgrading, verify the iocheckd service is functioning properly and confirm the device is responding to network requests.
  6. 6. As an additional mitigation, implement network segmentation to restrict access to the device's management interfaces to only trusted IP addresses, limiting exposure to unauthenticated attackers.
Caveat Review WAGO release notes for any configuration or feature changes between versions that may affect your deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Pfc 200 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA4.0 h
22.0 hours of engineering $3,860
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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-2019-5078 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data