CVE-2018-7838
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 · uneditedA CWE-119 Buffer Errors vulnerability exists in Modicon M580 CPU - BMEP582040, all versions before V2.90, and Modicon Ethernet Module BMENOC0301, all versions before V2.16, which could cause denial of service on the FTP service of the controller or the Ethernet BMENOC module when it receives a FTP CWD command with a data length greater than 1020 bytes. A power cycle is then needed to reactivate the FTP service.
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 buffer overflow vulnerability (CWE-119) in the FTP service of Modicon M580 CPU (BMEP582040) and Ethernet module (BMENOC0301) allows denial of service when processing a FTP CWD command with data exceeding 1020 bytes. The FTP service crashes and requires a power cycle to recover.
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< 2.16< 2.90< 2.90< 2.90< 2.90< 2.90< 2.90< 2.90CVSS 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 product modelLocate the model number on the physical device label or in the device configuration software (Unity Pro or EcoStruxure). Confirm it is one of: BMENOC0301, BMEP584040, BMEP586040, BMEH586040, BMEP581020, BMEP582020, BMEP582040, or BMEP583020.Affected if The product model matches one of the affected models listed in the CVE.
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Check the firmware versionAccess the device web interface, Unity Pro/EcoStruxure engineering station, or use the device's built-in diagnostics to retrieve the current firmware version. For M580 CPUs, look for firmware version under the CPU properties. For BMENOC0301, check the Ethernet module firmware.Affected if The installed firmware version is below 2.90 for M580 models, or below 2.16 for BMENOC0301.
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Verify FTP service statusCheck the device configuration for the FTP server settings. In Unity Pro or EcoStruxure, navigate to the device communication settings. Alternatively, attempt to connect to the device on port 21 (FTP) from an authorized host to confirm the service is running.Affected if The FTP service is enabled and running on the device.
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Assess network exposure of FTP portPerform a port scan or check firewall rules to determine if port 21 is accessible from untrusted networks. Verify whether the device FTP port is exposed to the internet or unauthorized internal segments.Affected if Port 21 (FTP) is accessible from networks where untrusted users could send crafted CWD commands.
You are affected if your device is one of the listed models, runs firmware below 2.90 (M580) or 2.16 (BMENOC0301), has FTP service enabled, and the FTP port is network-accessible to untrusted users.
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 data2.162.90
Apply vendor firmware updates (V2.90+ for M580, V2.16+ for BMENOC0301). As an interim control, restrict network access to the FTP service (port 21) to prevent unauthenticated attackers from triggering the overflow.
- Consultation3.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-7838 — 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-2018-7838 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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- Version or environment caveats, and links to real fixes
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