CVE-2019-6811
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 · uneditedAn Improper Check for Unusual or Exceptional Conditions (CWE-754) vulnerability exists in Modicon Quantum 140 NOE771x1 version 6.9 and earlier, which could cause denial of service when the module receives an IP fragmented packet with a length greater than 65535 bytes. The module then requires a power cycle to recover.
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 confidenceA CWE-754 (Improper Check for Unusual or Exceptional Conditions) vulnerability in the Modicon Quantum 140 NOE771x1 network module versions 6.9 and earlier allows denial of service when the module processes a specially crafted IP fragmented packet with a length exceeding 65535 bytes. The device enters an unrecoverable fault state requiring a power cycle to restore functionality.
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<= 6.9<= 6.9CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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 checksWork through these to decide whether this CVE applies to you.
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Identify the Modicon Quantum network module modelLocate the physical hardware or check the device inventory for a Schneider Electric Modicon Quantum 140 NOE77101 or 140 NOE77111 network module. The model number is typically printed on the device label or visible in the network management interface.Affected if The model is 140 NOE77101 or 140 NOE77111
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Check the installed firmware versionAccess the network module through its web interface, management console, or Schneider Electric management software (such as Unity Pro or EcoStruxure). Navigate to the firmware version information page. Compare the displayed version against 6.9.Affected if The firmware version is 6.9 or earlier
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Verify network accessibility of the affected moduleDetermine if the module is directly accessible from network segments that contain untrusted or external traffic. Check firewall rules, VLAN configurations, and network segmentation policies around the industrial network where the module is deployed.Affected if The module is reachable from untrusted network segments without filtering of malformed IP fragments
You are affected if you have a Modicon Quantum 140 NOE77101 or 140 NOE77111 network module running firmware version 6.9 or earlier that is network-accessible to potential attackers.
Generated from the published advisory. Verify against your own configuration.
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 dataApply the vendor-supplied firmware update when available, and implement network segmentation/firewall rules to filter malformed IP fragments exceeding 65535 bytes and limit exposure of affected industrial network modules to untrusted networks.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $7,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-6811 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2019-6811 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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