# CVE-2021-27458: Denial of service in JTEKT Corporation TOYOPUC products

> An attacker can cause a denial of service by leaving Ethernet communication open, preventing connections with other devices in JTEKT TOYOPUC products.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-qmc4-q85x-pjh3

## What is CVE-2021-27458?

CVE-2021-27458 is a high-severity denial of service vulnerability in JTEKT Corporation TOYOPUC products, published on 19 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

If Ethernet communication of the JTEKT Corporation TOYOPUC product series’ (TOYOPUC-PC10 Series: PC10G-CPU TCC-6353: All versions, PC10GE TCC-6464: All versions, PC10P TCC-6372: All versions, PC10P-DP TCC-6726: All versions, PC10P-DP-IO TCC-6752: All versions, PC10B-P TCC-6373: All versions, PC10B TCC-1021: All versions, PC10B-E/C TCU-6521: All versions, PC10E TCC-4737: All versions; TOYOPUC-Plus Series: Plus CPU TCC-6740: All versions, Plus EX TCU-6741: All versions, Plus EX2 TCU-6858: All versions, Plus EFR TCU-6743: All versions, Plus EFR2 TCU-6859: All versions, Plus 2P-EFR TCU-6929: All versions, Plus BUS-EX TCU-6900: All versions; TOYOPUC-PC3J/PC2J Series: FL/ET-T-V2H THU-6289: All versions, 2PORT-EFR THU-6404: All versions) are left in an open state by an attacker, Ethernet communications cannot be established with other devices, depending on the settings of the link parameters.

Weakness: CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2021-27458?

It affects 18 products.


Products: Jtekt 2port-Efr Thu-6404 Firmware, Jtekt Fl\/Et-T-V2h Thu-6289 Firmware, Jtekt Pc10b-E\/C Tcu-6521 Firmware, Jtekt Pc10b-P Tcc-6373 Firmware, Jtekt Pc10b Tcc-1021 Firmware, Jtekt Pc10e Tcc-4737 Firmware, Jtekt Pc10g-Cpu Tcc-6353 Firmware, Jtekt Pc10ge Tcc-6464 Firmware, Jtekt Pc10p-Dp-Io Tcc-6752 Firmware, Jtekt Pc10p-Dp Tcc-6726 Firmware, Jtekt Pc10p Tcc-6372 Firmware, Jtekt Plus 2p-Efr Tcu-6929 Firmware, Jtekt Plus Bus-Ex Tcu-6900 Firmware, Jtekt Plus Cpu Tcc-6740 Firmware, Jtekt Plus Efr2 Tcu-6859 Firmware, Jtekt Plus Efr Tcu-6743 Firmware, Jtekt Plus Ex2 Tcu-6858 Firmware, Jtekt Plus Ex Tcu-6741 Firmware.

## How do I fix CVE-2021-27458?

No fix has been published for CVE-2021-27458 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27458 being exploited?

There is no known exploitation of CVE-2021-27458 in the wild and no public exploit code.

## Other vulnerabilities in JTEKT Corporation TOYOPUC products

- [CVE-2021-33011](https://insights.sbomify.com/CVE-2021-33011/): Denial of service in JTEKT Corporation TOYOPUC products (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27458 and fix it if it is affected.

What it is: CVE-2021-27458 is a high-severity denial of service vulnerability in JTEKT Corporation TOYOPUC products, published on 19 Apr 2021. 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-2021-27458 in the wild and no public exploit code.

Affected product: JTEKT Corporation TOYOPUC products. 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-2021-27458/ (Markdown: https://insights.sbomify.com/CVE-2021-27458/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27458
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27458
- OSV: https://osv.dev/vulnerability/CVE-2021-27458

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27458/
Summaries are generated and may contain mistakes; the official description above is the record.