CVE-2012-6436
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 · uneditedThe device does not properly validate the data being sent to the buffer. An attacker can send a malformed CIP packet to Port 2222/TCP, Port 2222/UDP, Port 44818/TCP, or Port 44818/UDP, which creates a buffer overflow and causes the CPU to crash. Successful exploitation of this vulnerability could cause loss of availability and a disruption in communications with other connected devices. Rockwell Automation EtherNet/IP products; 1756-ENBT, 1756-EWEB, 1768-ENBT, and 1768-EWEB communication modules; CompactLogix L32E and L35E controllers; 1788-ENBT FLEXLogix adapter; 1794-AENTR FLEX I/O EtherNet/IP adapter; ControlLogix 18 and earlier; CompactLogix 18 and earlier; GuardLogix 18 and earlier; SoftLogix 18 and earlier; CompactLogix controllers 19 and earlier; SoftLogix controllers 19 and earlier; ControlLogix controllers 20 and earlier; GuardLogix controllers 20 and earlier; and MicroLogix 1100 and 1400
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 in Rockwell Automation EtherNet/IP products (communication modules, controllers, and adapters) allows remote attackers to send malformed CIP packets to ports 2222/TCP, 2222/UDP, 44818/TCP, or 44818/UDP. The device does not properly validate incoming data before copying it to a buffer, causing a buffer overflow that crashes the CPU and disrupts communications with downstream devices.
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<= 20<= 20<= 1100<= 1400<= 19all versionsall versionsall 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
- 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 exposed EtherNet/IP portsScan network for open ports 2222/TCP, 2222/UDP, 44818/TCP, and 44818/UDP. Use nmap or network scanner: nmap -p 2222,44818 -sTU target_ip_rangeAffected if Any of these ports are open and accessible on your network
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Identify Controllogix or Guardlogix controllersCheck your asset inventory or query devices on the network for Rockwell Automation Controllogix or Guardlogix controllers. Use Rockwell FTL服务器 or check device web interfacesAffected if You have Controllogix controllers firmware version <= 20 or Guardlogix controllers firmware version <= 20
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Identify Micrologix or Softlogix devicesCheck asset inventory or scan for Micrologix 1100/1400 or Softlogix controllers on the network. Verify firmware versions via RSLinx or device web interfacesAffected if You have Micrologix 1100 or 1400 (any version) or Softlogix controllers firmware version <= 19
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Identify 1756-ENBT/EWEB or 1768-ENBT/EWEB modulesCheck ControlLogix chassis for 1756-ENBT, 1756-EWEB, 1768-ENBT, or 1768-EWEB communication modules. Verify module firmware via RSLinx or Studio 5000Affected if You have any 1756-ENBT, 1756-EWEB, 1768-ENBT, or 1768-EWEB module (all versions affected)
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Check for crash logs or communication disruptionsReview controller crash logs in RSLinx, Studio 5000, or PLC firmware logs. Look for unexpected CPU crashes or lost communication with downstream devicesAffected if You observe unexplained CPU crashes or intermittent communication failures on affected ports
You are affected if you have any Rockwell Automation devices from the affected product list with exposed ports 2222 or 44818, particularly Controllogix <=20, Guardlogix <=20, Micrologix, Softlogix <=19, or any 1756/1768 ENBT/EWEB modules.
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 vendor-supplied firmware updates for affected ControlLogix, CompactLogix, GuardLogix, SoftLogix, MicroLogix, and FLEXLogix products. Implement network segmentation and firewall rules to restrict access to ports 2222 and 44818, and monitor for malformed CIP traffic.
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- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-6436 — 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-2012-6436 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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