Modicon Tsxety4103 FirmwareOperating system · Schneider Electric

CVE-2020-7563

HIGH · 8.8 CVSS v3.1 Published 2020-11-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable 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
A CWE-787: Out-of-bounds Write vulnerability exists in the Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details) which could cause corruption of data, a crash, or code execution when uploading a specially crafted file on the controller over FTP.

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

Out-of-bounds write vulnerability (CWE-787) in the FTP server component of the web server on Schneider Electric Modicon M340, Quantum, and Premium PLCs. Successful exploitation allows authenticated attackers to upload specially crafted files that trigger memory corruption, potentially leading to data corruption, denial of service, or arbitrary code execution on the controller.

MitigationApply vendor firmware updates when available; if no patch exists, disable FTP access, implement network segmentation to restrict PLC access to trusted networks, and enforce strong authentication for any remaining management interfaces.

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
Modicon Tsxety4103 FirmwareOperating system
Affected:all versions
Modicon Tsxety5103 FirmwareOperating system
Affected:all versions
Modicon Tsxp574634 FirmwareOperating system
Affected:all versions
Modicon Tsxp575634 FirmwareOperating system
Affected:all versions
Modicon Tsxp576634 FirmwareOperating system
Affected:all versions
Modicon Quantum 140noe77101 FirmwareOperating system
Affected:all versions
Modicon Quantum 140noe77111 FirmwareOperating system
Affected:all versions
Modicon Quantum 140noc78100 FirmwareOperating system
Affected:all versions

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/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 PLC model
    Check the physical device label or access the PLC configuration/management interface to confirm the exact model number (Modicon M340, Quantum, or Premium).
    Affected if The PLC is a Schneider Electric Modicon M340, Quantum, or Premium controller.
  2. Identify firmware module versions
    Access the PLC firmware management interface or use the vendor configuration tool (such as Unity Pro or EcoStruxure) to list installed firmware modules. Look for modules Tsxety4103, Tsxety5103, Tsxp574634, Tsxp575634, Tsxp576634, 140noe77101, 140noe77111, or 140noc78100.
    Affected if Any of the following firmware modules are installed: Tsxety4103, Tsxety5103, Tsxp574634, Tsxp575634, Tsxp576634, 140noe77101, 140noe77111, or 140noc78100.
  3. Verify FTP server status
    Check the PLC network configuration settings or use network scanning tools to determine if the FTP server port (default port 21) is open and listening on the PLC network interface.
    Affected if FTP server is enabled and accessible on the PLC.
  4. Review FTP authentication configuration
    Examine the PLC management interface or configuration files to determine whether FTP authentication is configured and whether anonymous or default credentials are in use.
    Affected if FTP access is granted to authenticated users (any valid credentials can trigger the vulnerability).

A user is affected if they have a Modicon M340, Quantum, or Premium PLC with any of the listed firmware modules (all versions) and the FTP server is enabled and 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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor firmware updates when available; if no patch exists, disable FTP access, implement network segmentation to restrict PLC access to trusted networks, and enforce strong authentication for any remaining management interfaces.

Fix this in Modicon Tsxety4103 Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2020-7563 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