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Modicon Tsxety4103 FirmwareOperating system · Schneider Electric

CVE-2020-7562

HIGH · 8.1 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 →
87/100
Remediation priority · High
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-125: Out-of-Bounds Read 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 a segmentation fault or a buffer overflow 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 · high confidence

An out-of-bounds read vulnerability (CWE-125) exists in the Web Server component of Schneider Electric Modicon M340, Modicon Quantum, and Modicon Premium PLCs and their Communication Modules. The vulnerability is triggered by uploading a specially crafted malicious file over FTP, which can cause a segmentation fault or buffer overflow condition.

MitigationDisable or restrict FTP access on affected Modicon controllers if not operationally required; apply available firmware patches from Schneider Electric; implement network segmentation to limit exposure to trusted networks only.

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
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 Modicon PLC model
    Access the PLC engineering software (Unity Pro or EcoStruxure) or check the physical device label to determine the exact model number (e.g., 140noe77101, Tsxety5103)
    Affected if The model matches one of the affected variants: Tsxety4103, Tsxety5103, Tsxp574634, Tsxp575634, Tsxp576634, 140noe77101, 140noe77111, or 140noc78100
  2. Verify FTP server is enabled
    Check the PLC network configuration settings in the engineering software or through the device web interface for FTP server status
    Affected if FTP server is enabled on the device
  3. Confirm Web Server component is active
    In the PLC configuration, navigate to the Web Server settings (usually under Communication > Ethernet > Web Server) and verify if it is started or enabled
    Affected if Web Server component is running or enabled on the PLC
  4. Check for FTP access exposure
    Review network firewall rules or PLC access control lists to determine if port 21 (FTP) is reachable from untrusted network segments
    Affected if FTP service is accessible from outside the trusted operational network
  5. Review firmware version
    In the PLC programming software, access the PLC properties or use the 'Get CPU Info' command to display the firmware version string
    Affected if The installed firmware version matches one of the listed affected product firmware versions (all versions are affected)

The environment is affected if the PLC is one of the specific Modicon models (M340, Quantum, Premium) listed with an affected catalog number AND FTP server with Web Server component is enabled and accessible on the network.

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

Disable or restrict FTP access on affected Modicon controllers if not operationally required; apply available firmware patches from Schneider Electric; implement network segmentation to limit exposure to trusted networks only.

Fix this in Modicon Tsxety4103 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-2020-7562 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