# CVE-2012-6439: Rockwell Automation ControlLogix PLC Improper Access Control

> Unauthorized remote attackers can send crafted CIP messages to Rockwell PLCs to cause denial of service and disrupt communication.

- **Severity:** High 8.5 (`AV:N/AC:L/Au:N/C:N/I:P/A:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jan 2013
- **Updated:** 30 Jun 2025
- **Also known as:** GHSA-7q92-phh3-9wp8

## What is CVE-2012-6439?

CVE-2012-6439 is a high-severity missing authorization vulnerability in Rockwell Automation 1756-ENBT, 1756-EWEB, 1768-ENBT, 1768-EWEB communication modules, published on 24 Jan 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

When an affected 
product receives a valid CIP message from an unauthorized or unintended 
source to Port 2222/TCP, Port 2222/UDP, Port 44818/TCP, or Port 
44818/UDP that changes the product’s configuration and network 
parameters, a DoS condition can occur. This situation could cause loss 
of availability and a disruption of communication 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

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2012-6439?

It affects 17 products.


Products: Rockwellautomation 1756-Enbt, Rockwellautomation 1756-Eweb, Rockwellautomation 1768-Enbt, Rockwellautomation 1768-Eweb, Rockwellautomation 1794-Aentr Flex I\/O Ethernet\/Ip Adapter, Rockwellautomation Compactlogix, Rockwellautomation Compactlogix Controllers, Rockwellautomation Compactlogix L32e Controller, Rockwellautomation Compactlogix L35e Controller, Rockwellautomation Controllogix, Rockwellautomation Controllogix Controllers, Rockwellautomation Flexlogix 1788-Enbt Adapter, Rockwellautomation Guardlogix, Rockwellautomation Guardlogix Controllers, Rockwellautomation Micrologix, Rockwellautomation Softlogix, Rockwellautomation Softlogix Controllers.

## How do I fix CVE-2012-6439?

No fix has been published for CVE-2012-6439 yet. Limit exposure of the affected software until one is available.

## Is CVE-2012-6439 being exploited?

There is no known exploitation of CVE-2012-6439 in the wild and no public exploit code.

## Other vulnerabilities in Rockwell Automation 1756-ENBT, 1756-EWEB, 1768-ENBT, 1768-EWEB communication modules

- [CVE-2012-6437](https://insights.sbomify.com/CVE-2012-6437/): Rockwell Automation ControlLogix PLC Improper Authentication (critical 10.0)
- [CVE-2012-6440](https://insights.sbomify.com/CVE-2012-6440/): Rockwell Automation ControlLogix PLC Improper Input Validation (critical 9.3)
- [CVE-2012-6435](https://insights.sbomify.com/CVE-2012-6435/): Rockwell Automation ControlLogix PLC Improper Access Control (high 7.8)
- [CVE-2012-6436](https://insights.sbomify.com/CVE-2012-6436/): Rockwell Automation ControlLogix PLC Improper Input Validation (high 7.8)
- [CVE-2012-6438](https://insights.sbomify.com/CVE-2012-6438/): Rockwell Automation ControlLogix PLC Improper Input Validation (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2012-6439 and fix it if it is affected.

What it is: CVE-2012-6439 is a high-severity missing authorization vulnerability in Rockwell Automation 1756-ENBT, 1756-EWEB, 1768-ENBT, 1768-EWEB communication modules, published on 24 Jan 2013. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2012-6439 in the wild and no public exploit code.

Affected product: Rockwell Automation 1756-ENBT, 1756-EWEB, 1768-ENBT, 1768-EWEB communication modules. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2012-6439/ (Markdown: https://insights.sbomify.com/CVE-2012-6439/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2012-6439
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2012-6439
- OSV: https://osv.dev/vulnerability/CVE-2012-6439

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From sbomify Insights: https://insights.sbomify.com/CVE-2012-6439/
Summaries are generated and may contain mistakes; the official description above is the record.