CVE-2009-3739
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 · uneditedMultiple unspecified vulnerabilities on the Rockwell Automation AB Micrologix 1100 and 1400 controllers allow remote attackers to obtain privileged access or cause a denial of service (halt) via unknown vectors.
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 confidenceMultiple critical vulnerabilities in Rockwell Automation Micrologix 1100 and 1400 PLCs allow remote attackers to gain privileged (administrator-level) access or cause a denial of service that halts the controller. The specific vulnerability types and attack vectors are not disclosed in available sources.
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 dataall versionsall versionsCVSS 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 checksWork through these to decide whether this CVE applies to you.
-
Identify Micrologix 1100 or 1400 controllers on the networkUse network scanning tools (such as Nmap) or industrial asset discovery tools to identify devices with vendor ID for Rockwell Automation and product identifiers matching Micrologix 1100 or 1400. Check network diagrams, asset inventories, or PLC programming software for these device models.Affected if Any Micrologix 1100 or Micrologix 1400 controller is found on the network
-
Verify controller accessibility from untrusted networksReview firewall rules, network segmentation, and access control lists to determine whether the PLC management interfaces or communication ports (TCP 44818 for EtherNet/IP, HTTP on port 80/443 if web server enabled) are exposed to untrusted or external networks.Affected if The PLC is reachable from untrusted network segments or directly from the internet
-
Check for enabled remote management interfacesInspect the PLC configuration via RSLogix/Rockwell programming software to determine if remote protocols such as HTTP, FTP, or remote access features are enabled. Use network packet capture to detect traffic to these services.Affected if Remote management or programming interfaces are enabled and accessible
-
Confirm firmware version for inventory purposesIf direct access to the PLC is available, use RSLinx or similar Rockwell software to query the controller for its firmware version. Document this for asset tracking even though all versions are affected.Affected if Any firmware version is returned, confirming the device is a Micrologix 1100 or 1400
If any Micrologix 1100 or 1400 controller exists in the environment and is network-accessible, it is affected by this CVE since all versions are vulnerable.
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 dataGiven the CVSS 10 severity and remote exploitability, prioritize network segmentation to isolate PLCs from untrusted networks, implement strict access controls, and apply any vendor-supplied firmware updates if available. If patches are unavailable, consider compensating controls such as firewalls and monitoring.
- Consultation16.0 h
- Implementation24.0 h
- Testing16.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $18,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2009-3739 — 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-2009-3739 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
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.
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.
- 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