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Micrologix 1400 A FirmwareOperating system · Rockwellautomation

CVE-2020-6988

HIGH · 7.5 CVSS v3.1 Published 2020-03-16
Fix available
A fix is available. Upgrade to after 21.001 or later.
See remediation →
84/100
Remediation priority · High
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
Rockwell Automation MicroLogix 1400 Controllers Series B v21.001 and prior, Series A, all versions, MicroLogix 1100 Controller, all versions, RSLogix 500 Software v12.001 and prior, A remote, unauthenticated attacker can send a request from the RSLogix 500 software to the victim’s MicroLogix controller. The controller will then respond to the client with used password values to authenticate the user on the client-side. This method of authentication may allow an attacker to bypass authentication altogether, disclose sensitive information, or leak credentials.

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 vulnerability in MicroLogix 1400 and 1100 controllers allows an unauthenticated remote attacker to send a specially crafted request from RSLogix 500 software to the target controller. The controller responds with used password values, enabling credential disclosure and potential authentication bypass.

MitigationUpdate MicroLogix 1400 Series B to firmware v21.002 or later, RSLogix 500 to v12.002 or later. For legacy systems without updates, implement network segmentation and restrict access to controllers via firewalls or VLANs.

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
Micrologix 1400 A FirmwareOperating system
Affected:all versions
Micrologix 1400 B FirmwareOperating system
Affected:<= 21.001
Micrologix 1100 FirmwareOperating system
Affected:all versions
Rslogix 500Application
Affected:<= 12.001

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
None
Availability
None

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

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 MicroLogix controller firmware version
    Access the controller via RSLogix 500 or check the controller's web interface (if available) to view the firmware version. For command-line access, use the appropriate diagnostic tool or consult controller documentation.
    Affected if The controller is a MicroLogix 1400 A (any version), MicroLogix 1400 B version 21.001 or earlier, or MicroLogix 1100 (any version).
  2. Identify RSLogix 500 software version
    Open RSLogix 500, then navigate to Help > About RSLogix 500 to view the installed software version.
    Affected if The installed RSLogix 500 version is 12.001 or earlier.
  3. Verify controller network accessibility
    Check network configuration to determine if the controller has an IP address and is reachable from network segments outside the local control system. Review firewall rules and VLAN configurations.
    Affected if The controller is directly accessible from untrusted network segments or has no network segmentation in place.
  4. Check controller password configuration
    Examine the controller's security settings via RSLogix 500 by connecting to the controller and reviewing the controller properties for any configured password protection.
    Affected if A password is configured on the controller, as the vulnerability enables disclosure of these stored password values.

You are affected if your controller is a MicroLogix 1400 A (any version), 1400 B (version 21.001 or earlier), or 1100 (any version); or if RSLogix 500 version 12.001 or earlier is in use, and the controller is network-accessible to untrusted sources.

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.

From vendor data
Upgrade available Upgrade to a release after 21.001
Interim mitigation

Update MicroLogix 1400 Series B to firmware v21.002 or later, RSLogix 500 to v12.002 or later. For legacy systems without updates, implement network segmentation and restrict access to controllers via firewalls or VLANs.

Fix this in Micrologix 1400 A 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-2020-6988 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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