# CVE-2020-5652: Denial of service in MELSEC iQ-R, Q and L series

> Remote unauthenticated attackers can cause denial of service on Mitsubishi MELSEC PLCs by sending specially crafted packets to the Ethernet port.

- **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:** 30 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-cpv9-4hm5-jjhj

## What is CVE-2020-5652?

CVE-2020-5652 is a high-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-R, Q and L series, published on 30 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Uncontrolled resource consumption vulnerability in Ethernet Port on MELSEC iQ-R, Q and L series CPU modules (R 00/01/02 CPU firmware versions '20' and earlier, R 04/08/16/32/120 (EN) CPU firmware versions '52' and earlier, R 08/16/32/120 SFCPU firmware versions '22' and earlier, R 08/16/32/120 PCPU all versions, R 08/16/32/120 PSFCPU all versions, R 16/32/64 MTCPU all versions, Q03 UDECPU, Q 04/06/10/13/20/26/50/100 UDEHCPU serial number '22081' and earlier , Q 03/04/06/13/26 UDVCPU serial number '22031' and earlier, Q 04/06/13/26 UDPVCPU serial number '22031' and earlier, Q 172/173 DCPU all versions, Q 172/173 DSCPU all versions, Q 170 MCPU all versions, Q 170 MSCPU all versions, L 02/06/26 CPU (-P) and L 26 CPU - (P) BT all versions) allows a remote unauthenticated attacker to stop the Ethernet communication functions of the products via a specially crafted packet, which may lead to a denial of service (DoS) condition .

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-5652?

It affects 51 products.


Products: Mitsubishielectric Melsec Iq-R00cpu Firmware, Mitsubishielectric Melsec Iq-R01cpu Firmware, Mitsubishielectric Melsec Iq-R02cpu Firmware, Mitsubishielectric Melsec Iq-R04encpu Firmware, Mitsubishielectric Melsec Iq-R08encpu Firmware, Mitsubishielectric Melsec Iq-R08pcpu Firmware, Mitsubishielectric Melsec Iq-R08psfcpu Firmware, Mitsubishielectric Melsec Iq-R08sfcpu Firmware, Mitsubishielectric Melsec Iq-R120encpu Firmware, Mitsubishielectric Melsec Iq-R120pcpu Firmware, Mitsubishielectric Melsec Iq-R120psfcpu Firmware, Mitsubishielectric Melsec Iq-R120sfcpu Firmware, Mitsubishielectric Melsec Iq-R16encpu Firmware, Mitsubishielectric Melsec Iq-R16mtcpu Firmware, Mitsubishielectric Melsec Iq-R16pcpu Firmware, Mitsubishielectric Melsec Iq-R16psfcpu Firmware, Mitsubishielectric Melsec Iq-R16sfcpu Firmware, Mitsubishielectric Melsec Iq-R32encpu Firmware, Mitsubishielectric Melsec Iq-R32mtcpu Firmware, Mitsubishielectric Melsec Iq-R32pcpu Firmware and 31 more.

## How do I fix CVE-2020-5652?

No fix has been published for CVE-2020-5652 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-5652 being exploited?

There is no known exploitation of CVE-2020-5652 in the wild and no public exploit code.

## Other vulnerabilities in Mitsubishi Electric Corporation MELSEC iQ-R, Q and L series

- [CVE-2020-13238](https://insights.sbomify.com/CVE-2020-13238/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5652 and fix it if it is affected.

What it is: CVE-2020-5652 is a high-severity denial of service vulnerability in Mitsubishi Electric Corporation MELSEC iQ-R, Q and L series, published on 30 Oct 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-2020-5652 in the wild and no public exploit code.

Affected product: Mitsubishi Electric Corporation MELSEC iQ-R, Q and L series. 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-2020-5652/ (Markdown: https://insights.sbomify.com/CVE-2020-5652/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5652
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5652
- OSV: https://osv.dev/vulnerability/CVE-2020-5652

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-5652/
Summaries are generated and may contain mistakes; the official description above is the record.