dbcve.org
750 362 FirmwareOperating system · Wago

CVE-2020-12506

CRITICAL · 9.1 CVSS v3.1 Published 2020-09-30
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
Improper Authentication vulnerability in WAGO 750-8XX series with FW version <= FW03 allows an attacker to change the settings of the devices by sending specifically constructed requests without authentication This issue affects: WAGO 750-362, WAGO 750-363, WAGO 750-823, WAGO 750-832/xxx-xxx, WAGO 750-862, WAGO 750-891, WAGO 750-890/xxx-xxx in versions FW03 and prior versions.

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 WAGO 750-8XX series PLCs (including 750-362, 750-363, 750-823, 750-832, 750-862, 750-891, and 750-890) with firmware FW03 and prior versions contain an improper authentication vulnerability that allows unauthenticated attackers to change device settings by sending specifically crafted HTTP requests to the web interface.

MitigationUpdate WAGO 750-8XX devices to firmware version FW04 or later to patch the authentication bypass. If immediate patching is not possible, restrict network access to the devices via firewalls or network segmentation to minimize exposure.

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
750 362 FirmwareOperating system
Affected:<= fw03
750 363 FirmwareOperating system
Affected:<= fw03
750 823 FirmwareOperating system
Affected:<= fw03
750 832 FirmwareOperating system
Affected:<= fw03
750 862 FirmwareOperating system
Affected:<= fw03
750 891 FirmwareOperating system
Affected:<= fw03
750 890 FirmwareOperating system
Affected:<= fw03

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 the device model
    Locate the PLC model number on the physical device or in the device documentation/web interface. Confirm it is one of: 750-362, 750-363, 750-823, 750-832, 750-862, 750-891, or 750-890.
    Affected if The device is one of these specific models.
  2. Check the firmware version
    Access the device web interface or use the WAGO management software to view the installed firmware version. Look for a version designation labeled FW03 or earlier.
    Affected if The firmware version is FW03 or any version prior to FW03.
  3. Verify the web interface is enabled
    Check the device configuration to confirm the built-in HTTP web interface is enabled. This is typically found in the device network settings or web-based management settings.
    Affected if The web interface is enabled and accessible.
  4. Assess network accessibility
    Determine if the device web interface (port 80/443) is reachable from network segments outside the trusted control network. Check firewall rules and network segmentation policies.
    Affected if The web interface is exposed to untrusted networks or the internet.

You are affected if you have a WAGO 750-362, 750-363, 750-823, 750-832, 750-862, 750-891, or 750-890 PLC running firmware FW03 or earlier with the web interface enabled and network-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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update WAGO 750-8XX devices to firmware version FW04 or later to patch the authentication bypass. If immediate patching is not possible, restrict network access to the devices via firewalls or network segmentation to minimize exposure.

Recommended fix Moderate confidence

Firmware version newer than FW03 (contact WAGO for exact fixed release)

  1. Contact WAGO technical support to obtain the latest firmware version for your specific device model (750-362, 750-363, 750-823, 750-832, 750-862, 750-891, or 750-890)
  2. Request firmware version newer than FW03 (e.g., FW04 or later) that addresses CVE-2020-12506
  3. Follow WAGO's official firmware update procedure, typically involving the WAGO Ethernet Settings or e!COCKPIT software
  4. After upgrade, verify the device is no longer vulnerable by confirming the new firmware version
  5. If upgrading is not immediately possible, isolate affected devices on a separate network segment with strict access controls
Caveat Review WAGO release notes for any configuration or compatibility changes between FW03 and the new version

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

Fix this in 750 362 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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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-2020-12506 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