dbcve.org
Microsmart Fc6a FirmwareOperating system · Idec

CVE-2021-20827

HIGH · 7.5 CVSS v3.1 Published 2021-12-24
Fix available
A fix is available. Upgrade to after 8.19.1 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
Plaintext storage of a password vulnerability in IDEC PLCs (FC6A Series MICROSmart All-in-One CPU module v2.32 and earlier, FC6A Series MICROSmart Plus CPU module v1.91 and earlier, WindLDR v8.19.1 and earlier, WindEDIT Lite v1.3.1 and earlier, and Data File Manager v2.12.1 and earlier) allows an attacker to obtain the PLC Web server user credentials from file servers, backup repositories, or ZLD files saved in SD cards. As a result, the attacker may access the PLC Web server and hijack the PLC, and manipulation of the PLC output and/or suspension of the PLC may be conducted.

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

IDEC PLCs and associated software store user credentials in plaintext within backup files, ZLD files on SD cards, and file server repositories. An attacker who gains access to these storage locations can extract credentials and authenticate to the PLC web server, enabling manipulation of PLC outputs or denial of service.

MitigationUpdate affected products to patched versions (FC6A All-in-One v2.33+, Plus v1.92+, WindLDR v8.19.2+, WindEDIT Lite v1.3.2+, Data File Manager v2.12.2+). Additionally, secure backup repositories, encrypt stored credentials, restrict access to SD cards, and implement network segmentation for PLCs.

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
Microsmart Fc6a FirmwareOperating system
Affected:<= 2.32
Microsmart Plus Fc6a FirmwareOperating system
Affected:<= 1.91
Data File ManagerApplication
Affected:<= 2.12.1
WindeditApplication
Affected:<= 1.3.1
WindldrApplication
Affected:<= 8.19.1

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. Check PLC firmware version on Microsmart Fc6a
    Access the PLC web interface or use the WindLDR programming software to read the firmware version. In WindLDR, navigate to Controller > Controller Setup or check the system information. For web interface, log in and check the version under System or About.
    Affected if Firmware version is 2.32 or lower for standard Fc6a, or 1.91 or lower for Fc6a Plus
  2. Check installed software versions
    Open the installed application (Data File Manager, WindEDIT, or WindLDR) and navigate to Help > About or the version information dialog to determine the installed version number.
    Affected if Data File Manager is 2.12.1 or lower, WindEDIT is 1.3.1 or lower, or WindLDR is 8.19.1 or lower
  3. Locate backup files on file servers or local storage
    Search for .zld files, .bak files, or backup archives in shared folders, file servers, and local directories where IDEC project files are stored. Use file system search for patterns like *.zld, *.bak, backup*, *backup*.
    Affected if Plaintext credentials are found within backup files, ZLD files, or project files in storage locations
  4. Inspect SD cards used with PLCs
    If an SD card is used with the PLC, remove it and examine the contents on a separate system. Look for ZLD files or other project files stored on the SD card and inspect them for plaintext username and password strings.
    Affected if ZLD files on the SD card contain readable plaintext credentials

You are affected if any of the following are true: (1) Fc6a firmware is 2.32 or lower (or Plus is 1.91 or lower), (2) Data File Manager is 2.12.1 or lower, WindEDIT is 1.3.1 or lower, or WindLDR is 8.19.1 or lower, AND (3) you have backup files, ZLD files on SD cards, or project files in file repositories that contain plaintext credentials.

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 a release after 8.19.1
Interim mitigation

Update affected products to patched versions (FC6A All-in-One v2.33+, Plus v1.92+, WindLDR v8.19.2+, WindEDIT Lite v1.3.2+, Data File Manager v2.12.2+). Additionally, secure backup repositories, encrypt stored credentials, restrict access to SD cards, and implement network segmentation for PLCs.

Recommended fix Moderate confidence

FC6A Series MICROSmart All-in-One CPU module: v2.33+ | FC6A Series MICROSmart Plus CPU module: v1.92+ | WindLDR: v8.20+ | WindEDIT Lite: v1.4.0+ | Data File Manager: v2.13+

  1. 1. Identify all affected IDEC products in your environment: FC6A Series MICROSmart All-in-One CPU modules, FC6A Series MICROSmart Plus CPU modules, WindLDR, WindEDIT Lite, and Data File Manager.
  2. 2. Determine current firmware/software versions of each affected product.
  3. 3. For FC6A Series MICROSmart All-in-One CPU modules: Upgrade firmware to version 2.33 or later.
  4. 4. For FC6A Series MICROSmart Plus CPU modules: Upgrade firmware to version 1.92 or later.
  5. 5. For WindLDR: Upgrade to version 8.20 or later.
  6. 6. For WindEDIT Lite: Upgrade to version 1.4.0 or later.
  7. 7. For Data File Manager: Upgrade to version 2.13 or later.
  8. 8. After upgrading, verify that credentials are no longer stored in plaintext in backup files, ZLD files, and SD card exports.
Caveat Minor: Ensure compatibility of updated WindLDR/WindEDIT projects with newer software versions; firmware updates may require PLC program review

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

Fix this in Microsmart Fc6a Firmware Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-20827 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-20827 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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