# CVE-2021-22742: Denial of service in Triconex Model 3009 MP installed on Tricon V11.3.x systems

> Malformed packets can reset the Triconex module when the write-protect keyswitch is in the program position, causing a denial of service.

- **Severity:** Low 3.9 (`CVSS:3.1/AV:P/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-xv33-m47j-6p6j

## What is CVE-2021-22742?

CVE-2021-22742 is a low-severity denial of service vulnerability in Triconex Model 3009 MP installed on Tricon V11.3.x systems, published on 26 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Improper Check for Unusual or Exceptional Conditions vulnerability exists in Triconex Model 3009 MP installed on Tricon V11.3.x systems that could cause module reset when TCM receives malformed TriStation packets while the write-protect keyswitch is in the program position.

Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions)

## Which versions are affected by CVE-2021-22742?

It affects 2 products.


Products: Schneider-Electric Tcm 4351b Firmware, Schneider-Electric Triconex Model 3009 Mp Firmware.

## How do I fix CVE-2021-22742?

No fix has been published for CVE-2021-22742 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-22742 being exploited?

There is no known exploitation of CVE-2021-22742 in the wild and no public exploit code.

## Other vulnerabilities in Triconex Model 3009 MP installed on Tricon V11.3.x systems

- [CVE-2021-22743](https://insights.sbomify.com/CVE-2021-22743/): Denial of service in Triconex TCM 4351B installed on Tricon V11.3.x systems. (low 3.9)
- [CVE-2021-22744](https://insights.sbomify.com/CVE-2021-22744/): Denial of service in Triconex Model 3009 MP installed on Tricon V11.3.x systems (low 3.9)
- [CVE-2021-22745](https://insights.sbomify.com/CVE-2021-22745/): Denial of service in Triconex Model 3009 MP installed on Tricon V11.3.x systems (low 3.9)
- [CVE-2021-22746](https://insights.sbomify.com/CVE-2021-22746/): Denial of service in Triconex Model 3009 MP installed on Tricon V11.3.x systems (low 3.9)
- [CVE-2021-22747](https://insights.sbomify.com/CVE-2021-22747/): Denial of service in Triconex Model 3009 MP installed on Tricon V11.3.x systems (low 3.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-22742 and fix it if it is affected.

What it is: CVE-2021-22742 is a low-severity denial of service vulnerability in Triconex Model 3009 MP installed on Tricon V11.3.x systems, published on 26 May 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-22742 in the wild and no public exploit code.

Affected product: Triconex Model 3009 MP installed on Tricon V11.3.x systems. 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-2021-22742/ (Markdown: https://insights.sbomify.com/CVE-2021-22742/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-22742
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-22742
- OSV: https://osv.dev/vulnerability/CVE-2021-22742

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-22742/
Summaries are generated and may contain mistakes; the official description above is the record.