# CVE-2020-12739: Denial of service in n/a

> An unauthenticated remote attacker can cause a Fanuc CNC controller to become inaccessible, disrupting industrial operations.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Aug 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-qrgc-2qmf-qw4g

## What is CVE-2020-12739?

CVE-2020-12739 is a medium-severity denial of service vulnerability in n/a, published on 3 Aug 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A denial-of-service vulnerability in the Fanuc i Series CNC (0i-MD and 0i Mate-MD) could allow an unauthenticated, remote attacker to cause an affected CNC to become inaccessible to other devices.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-12739?

It affects 16 products.


Products: Fanuc Power Motion I-Model a Firmware, Fanuc Series 0i-Mate D Firmware, Fanuc Series 0i-Model B Firmware, Fanuc Series 0i-Model C Firmware, Fanuc Series 0i-Model D Firmware, Fanuc Series 0i-Model F Firmware, Fanuc Series 0i-Model F Plus Firmware, Fanuc Series 16i Firmware, Fanuc Series 18i-Wb Firmware, Fanuc Series 18i Firmware, Fanuc Series 21i-Model B Firmware, Fanuc Series 30i Firmware, Fanuc Series 31i Firmware, Fanuc Series 32i-B Plus Firmware, Fanuc Series 32i-Model a Firmware, Fanuc Series 35i-B Firmware.

## How do I fix CVE-2020-12739?

No fix has been published for CVE-2020-12739 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-12739 being exploited?

There is no known exploitation of CVE-2020-12739 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-12739 and fix it if it is affected.

What it is: CVE-2020-12739 is a medium-severity denial of service vulnerability in n/a, published on 3 Aug 2020. 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-2020-12739 in the wild and no public exploit code.

Affected product: n/a. 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-2020-12739/ (Markdown: https://insights.sbomify.com/CVE-2020-12739/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-12739
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-12739
- OSV: https://osv.dev/vulnerability/CVE-2020-12739

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-12739/
Summaries are generated and may contain mistakes; the official description above is the record.