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750 893 FirmwareOperating system · Wago

CVE-2021-30190

CRITICAL · 9.8 CVSS v3.1 Published 2021-05-25
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
CODESYS V2 Web-Server before 1.1.9.20 has Improper Access Control.

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

CODESYS V2 Web-Server before version 1.1.9.20 contains an improper access control vulnerability. This critical flaw (CVSS 9.8) allows unauthorized users to bypass access restrictions in the web server component, potentially exposing sensitive control system interfaces or data.

MitigationUpgrade CODESYS V2 Web-Server to version 1.1.9.20 or later. If immediate patching is not feasible, restrict network access to the web server via firewall rules or disable the web server if not required.

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
750 893 FirmwareOperating system
Affected:< fw08
750 891 FirmwareOperating system
Affected:< fw08
750 890 FirmwareOperating system
Affected:< fw08
750 889 FirmwareOperating system
Affected:< fw15
750 885 FirmwareOperating system
Affected:< fw15
750 882 FirmwareOperating system
Affected:< fw15
750 881 FirmwareOperating system
Affected:< fw15
750 880 FirmwareOperating system
Affected:< fw16

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 750 controller model
    Locate the product label or access the controller's system information to confirm the exact model number (750-880, 750-881, 750-882, 750-885, 750-889, 750-890, 750-891, or 750-893)
    Affected if The model is any of the eight listed Wago 750 series controllers
  2. Determine the installed firmware version
    Access the controller via its management interface or use the appropriate configuration tool to read the current firmware version. Compare against the affected thresholds: < fw08 for models 893/891/890, < fw15 for models 889/885/882/881, < fw16 for model 880
    Affected if The firmware version is below the threshold specified for that model
  3. Verify if CODESYS V2 Web Server is enabled
    Check the controller configuration or services list for the CODESYS V2 Web Server component. On the web server, look for the 'webserver' or 'spider' service process
    Affected if The CODESYS V2 Web Server component is installed and running
  4. Confirm network accessibility of the web interface
    Attempt to access the web server via HTTP/HTTPS on the configured port (typically 80/443 or 8080) from an unauthorized network location, or review access logs for connections from untrusted networks
    Affected if The web interface is exposed on the network without proper access controls

You are affected if you have a Wago 750 series controller (880/881/882/885/889/890/891/893) with firmware below the specified threshold AND the CODESYS V2 Web Server is enabled and accessible on the network.

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

Upgrade CODESYS V2 Web-Server to version 1.1.9.20 or later. If immediate patching is not feasible, restrict network access to the web server via firewall rules or disable the web server if not required.

Recommended fix High confidence

CODESYS V2 Web-Server version 1.1.9.20 or later; Controller firmware: fw08 (750 893/891/890), fw15 (750 889/885/882/881), fw16 (750 880)

  1. 1. Identify the specific 750 controller model in your environment (750 880, 750 881, 750 882, 750 885, 750 889, 750 890, 750 891, or 750 893)
  2. 2. Check the current firmware version of the affected controller(s) using the CODESYS development environment or controller web interface
  3. 3. Obtain the firmware update from the controller manufacturer (WAGO or relevant OEM) or from customers.codesys.com
  4. 4. For 750 893, 750 891, and 750 890: upgrade firmware to version fw08 or later
  5. 5. For 750 889, 750 885, 750 882, and 750 881: upgrade firmware to version fw15 or later
  6. 6. For 750 880: upgrade firmware to version fw16 or later
  7. 7. After firmware update, verify the CODESYS V2 Web-Server version is 1.1.9.20 or later
  8. 8. Test that the web server functionality operates normally after the update
Caveat Firmware updates may require controller downtime and should be tested in a non-production environment first; verify compatibility with your specific PLC program and hardware configuration

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

Fix this in 750 893 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,480
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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-2021-30190 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data