Bmxnoc0401Hardware / appliance · Schneider Electric

CVE-2015-7937

HIGH · 10.0 CVSS v2.0 Published 2015-12-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
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
Stack-based buffer overflow in the GoAhead Web Server on Schneider Electric Modicon M340 PLC BMXNOx and BMXPx devices allows remote attackers to execute arbitrary code via a long password in HTTP Basic Authentication data.

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

A stack-based buffer overflow vulnerability exists in the GoAhead Web Server running on Schneider Electric Modicon M340 PLCs (BMXNOx and BMXPx models). The vulnerability is triggered by sending an excessively long password within HTTP Basic Authentication headers, allowing remote attackers to overflow a stack buffer and execute arbitrary code with the privileges of the web server.

MitigationApply available firmware updates from Schneider Electric. If no patch is available, restrict network access to the PLC's web interface using firewalls or network segmentation, and consider disabling the web server if not operationally required.

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
Bmxnoc0401Hardware / appliance
Affected:all versions
Bmxnoe0100Hardware / appliance
Affected:all versions
Bmxnoe0100hHardware / appliance
Affected:all versions
Bmxnoe0110Hardware / appliance
Affected:all versions
Bmxnoe0110hHardware / appliance
Affected:all versions
Bmxnor0200Hardware / appliance
Affected:all versions
Bmxnor0200hHardware / appliance
Affected:all versions
Bmxpra0100Hardware / appliance
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
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

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 PLC model number
    Locate the Schneider Electric PLC model identification label on the physical hardware or query the PLC runtime for its model designation (BMXNOx or BMXPx family)
    Affected if The model is one of: Bmxnoc0401, Bmxnoe0100, Bmxnoe0100h, Bmxnoe0110, Bmxnoe0110h, Bmxnor0200, Bmxnor0200h, or Bmxpra0100
  2. Verify the GoAhead Web Server is enabled
    Check the PLC configuration or web server settings to determine if the GoAhead HTTP service is running and listening on the network
    Affected if The GoAhead web server is enabled and actively listening for HTTP connections on the PLC
  3. Confirm HTTP Basic Authentication is configured
    Examine the web server authentication configuration to verify that Basic Authentication is the selected or default authentication method
    Affected if HTTP Basic Authentication is enabled as the authentication mechanism for the web interface
  4. Check network accessibility of the web interface
    Probe the PLC IP address on port 80/443 or the configured HTTP port to confirm the web server is network-accessible
    Affected if The PLC web interface is reachable from any network segment beyond the isolated control system network

If the PLC is a Modicon M340 model (BMXNOx or BMXPx family) with the GoAhead web server enabled and HTTP Basic Authentication configured, and the web interface is network-accessible, the environment is vulnerable to CVE-2015-7937.

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 available firmware updates from Schneider Electric. If no patch is available, restrict network access to the PLC's web interface using firewalls or network segmentation, and consider disabling the web server if not operationally required.

Fix this in Bmxnoc0401 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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Scan for this in your stack

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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-2015-7937 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