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750 8100 FirmwareOperating system · Wago

CVE-2021-34569

CRITICAL · 9.8 CVSS v3.1 Published 2022-11-09
Fix available
A fix is available. Upgrade to 18 or later.
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
In WAGO I/O-Check Service in multiple products an attacker can send a specially crafted packet containing OS commands to crash the diagnostic tool and write memory.

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 · moderate confidence

WAGO I/O-Check Service contains a command injection vulnerability allowing remote attackers to send specially crafted packets containing OS commands. This can cause denial of service by crashing the diagnostic tool and enables arbitrary memory writes, potentially allowing remote code execution.

MitigationApply vendor patches for affected WAGO products, restrict network access to the I/O-Check Service using firewalls or network segmentation, and disable the service if not required in production environments.

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
750 8100 FirmwareOperating system
Affected:< 18= 18
750 8101 FirmwareOperating system
Affected:< 18= 18
750 8101\/025 000 FirmwareOperating system
Affected:< 18= 18
750 8102 FirmwareOperating system
Affected:< 18= 18
750 8102\/025 000 FirmwareOperating system
Affected:< 18= 18
750 8202 FirmwareOperating system
Affected:< 18= 18
750 8202\/000 011 FirmwareOperating system
Affected:< 18= 18
750 8202\/000 012 FirmwareOperating system
Affected:< 18= 18

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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 the WAGO device model
    Access the device's web interface or check the physical label to determine the exact model number (e.g., 750-8100, 750-8101, 750-8202)
    Affected if The device model is one of the listed affected models: 750 8100, 750 8101, 750 8101/025 000, 750 8102, 750 8102/025 000, 750 8202, 750 8202/000 011, or 750 8202/000 012
  2. Check the installed firmware version
    Log into the device's web interface or use WAGO's management software to view the firmware version information
    Affected if The firmware version is less than 18 or exactly version 18
  3. Determine if the I/O-Check Service is enabled
    Access the device's service configuration or check running services via the device's admin interface to see if the I/O-Check Service is active
    Affected if The I/O-Check Service is enabled and running on the device
  4. Assess network accessibility of the I/O-Check Service
    Review network firewall rules, ACLs, or VLAN configuration to determine if the I/O-Check Service port is exposed to untrusted networks
    Affected if The I/O-Check Service is reachable from external or untrusted network segments

The device is affected if it is one of the listed WAGO 750 series models running firmware version 18 or lower, with the I/O-Check Service enabled and accessible.

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
Upgrade available Upgrade to 18 or later
Fixed in 18
Interim mitigation

Apply vendor patches for affected WAGO products, restrict network access to the I/O-Check Service using firewalls or network segmentation, and disable the service if not required in production environments.

Recommended fix High confidence

Firmware version 19 or later (e.g., latest stable 750 series firmware)

  1. 1. Identify the specific WAGO 750 series controller model (8100, 8101, 8102, or 8202) in your environment
  2. 2. Check the current firmware version of the affected device(s) using WAGO's web-based management interface or PFC firmware tool
  3. 3. Download the latest firmware version (version 19 or higher) from the official WAGO download portal at www.wago.com or via cert.vde.com reference
  4. 4. Back up the current device configuration before performing the firmware update
  5. 5. Upload and install the firmware version 19 or later using WAGO's firmware update procedure (typically via PFC Firmware Tool or web interface)
  6. 6. After the update completes, verify the device is operational and the I/O-Check Service is functioning correctly
  7. 7. Confirm the firmware version has been successfully updated to > 18
Caveat Review WAGO release notes for any configuration or compatibility changes between version 18 and version 19; standard backup recommended before upgrade

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

Fix this in 750 8100 Firmware Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
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An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

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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-2021-34569 in production — separate from our analysis above.

No notes yet

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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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data