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852 303 FirmwareOperating system · Wago

CVE-2019-12550

CRITICAL · 9.8 CVSS v3.0 Published 2019-06-17
Fix available
A fix is available. Upgrade to 1.1.5.s0 / 1.1.6.s0 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
WAGO 852-303 before FW06, 852-1305 before FW06, and 852-1505 before FW03 devices contain hardcoded users and passwords that can be used to login via SSH and TELNET.

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

WAGO 852-303, 852-1305, and 852-1505 industrial controllers contain hardcoded usernames and passwords embedded in firmware that enable unauthenticated remote access via SSH and TELNET protocols. The CVSS 9.8 rating reflects trivial network-based exploitation of these default credentials.

MitigationUpdate firmware to patched versions (FW06 or later for 852-303/852-1305; FW03 or later for 852-1505), change all default credentials immediately, and disable or restrict SSH/TELNET access through network segmentation if possible.

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
852 303 FirmwareOperating system
Affected:< 1.2.2.s0
852 1305 FirmwareOperating system
Affected:< 1.1.6.s0
852 1505 FirmwareOperating system
Affected:< 1.1.5.s0

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:3.0/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 controller model
    Locate the model number on the device hardware label or access the device's web interface, CLI, or management console to confirm the exact model (852-303, 852-1305, or 852-1505)
    Affected if The model is one of 852-303, 852-1305, or 852-1505
  2. Determine the installed firmware version
    Access the device's web interface, CLI, or management system and retrieve the current firmware version string (often visible in system info, about, or status pages)
    Affected if Firmware version is below 1.2.2.s0 for 852-303, below 1.1.6.s0 for 852-1305, or below 1.1.5.s0 for 852-1505
  3. Check if SSH service is enabled and accessible
    Attempt to connect to the device on TCP port 22 (SSH) from an external network location, or review the device's service configuration to confirm SSH daemon is running and exposed
    Affected if SSH is enabled and reachable from any network segment other than a strictly isolated management VLAN
  4. Check if TELNET service is enabled and accessible
    Attempt to connect to the device on TCP port 23 (TELNET) from an external network location, or review the device's service configuration to confirm TELNET daemon is running and exposed
    Affected if TELNET is enabled and reachable from any network segment other than a strictly isolated management VLAN

The device is affected if it is a WAGO 852-303, 852-1305, or 852-1505 controller running firmware below the specified thresholds AND has SSH or TELNET services 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
Upgrade available Upgrade to 1.1.5.s0 / 1.1.6.s0 / 1.2.2.s0 or later
Fixed in 1.1.5.s01.1.6.s01.2.2.s0
Interim mitigation

Update firmware to patched versions (FW06 or later for 852-303/852-1305; FW03 or later for 852-1505), change all default credentials immediately, and disable or restrict SSH/TELNET access through network segmentation if possible.

Recommended fix High confidence

852-303: Firmware 1.2.2.s0 or later (FW06+); 852-1305: Firmware 1.1.6.s0 or later (FW06+); 852-1505: Firmware 1.1.5.s0 or later (FW03+)

  1. 1. Identify the current firmware version of the affected WAGO device (852-303, 852-1305, or 852-1505) via the web interface or console
  2. 2. Download the appropriate firmware update from the official WAGO support portal (www.wago.com) or contact WAGO technical support
  3. 3. Follow WAGO's standard firmware upgrade procedure, typically via the web-based firmware update feature or using WAGO's management tools
  4. 4. After upgrading, immediately change any default credentials and disable unused access methods (SSH/TELNET) if not required
  5. 5. Verify the upgrade was successful and the hardcoded accounts are no longer present
Caveat Review WAGO release notes for any compatibility considerations before upgrading production systems

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

Fix this in 852 303 Firmware Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing8.0 h
  • Review / QA4.0 h
30.0 hours of engineering $5,280
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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-2019-12550 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