Bmxnor0200h FirmwareOperating system · Schneider Electric

CVE-2019-6831

HIGH · 8.6 CVSS v3.1 Published 2019-09-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
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
A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists in BMXNOR0200H Ethernet / Serial RTU module (all firmware versions), which could cause disconnection of active connections when an unusually high number of IEC 60870- 5-104 packets are received by the module on port 2404/TCP.

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

The BMXNOR0200H Ethernet/Serial RTU module contains an improper check for unusual or exceptional conditions (CWE-754) when processing incoming IEC 60870-5-104 packets on port 2404/TCP. When the module receives an unusually high volume of these packets, it fails to handle the exceptional condition properly, causing active connections to drop and resulting in a denial-of-service condition.

MitigationApply vendor-provided firmware patches when available; in the interim, implement network segmentation and firewall rules to limit exposure to port 2404/TCP from untrusted networks, and consider rate-limiting or IDS monitoring for anomalous IEC 60870-5-104 traffic patterns.

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
Bmxnor0200h 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
None
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify BMXNOR0200H device in network
    Scan the network for devices with hostname, MAC OUI, or product identification matching the BMXNOR0200H RTU module. Consult network documentation or perform an SNMP/asset inventory scan to locate this specific hardware.
    Affected if The device BMXNOR0200H is present in the environment and connected to the network.
  2. Check BMXNOR0200H firmware version
    Access the device web interface, console, or use SNMP to retrieve the firmware version string from the BMXNOR0200H module.
    Affected if The device is running any firmware version - all versions of BMXNOR0200h firmware are affected by this vulnerability.
  3. Verify port 2404/TCP accessibility
    Perform a TCP port scan targeting port 2404 on the BMXNOR0200H device IP address to determine if the IEC 60870-5-104 service is exposed.
    Affected if Port 2404/TCP is open and reachable from the network segment being assessed.
  4. Confirm IEC 60870-5-104 protocol is enabled
    Check the device configuration via web UI, console, or configuration export to verify that the IEC 60870-5-104 protocol stack is actively enabled on the module.
    Affected if The IEC 60870-5-104 protocol is enabled and the device is accepting connections on port 2404/TCP.

If you have a BMXNOR0200H device with IEC 60870-5-104 enabled and port 2404/TCP exposed, you are affected since all firmware versions are vulnerable to this DoS condition.

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-provided firmware patches when available; in the interim, implement network segmentation and firewall rules to limit exposure to port 2404/TCP from untrusted networks, and consider rate-limiting or IDS monitoring for anomalous IEC 60870-5-104 traffic patterns.

Fix this in Bmxnor0200h Firmware Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2019-6831 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-6831 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