# CVE-2020-7564: Memory corruption in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details)

> A buffer overflow in the Modicon PLC web server allows attackers to execute arbitrary commands by uploading a specially crafted file via FTP.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 18 Nov 2020
- **Updated:** 29 May 2026
- **Also known as:** GHSA-m8xw-66cv-rfr6

## What is CVE-2020-7564?

CVE-2020-7564 is a medium-severity memory corruption vulnerability in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details), published on 18 Nov 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

A CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability exists in the Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details) which could cause write access and the execution of commands when uploading a specially crafted file on the controller over FTP.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2020-7564?

It affects 20 products.


Products: Schneider-Electric Modicon M340 Bmx Noc 0401 Firmware, Schneider-Electric Modicon M340 Bmx Noe 0100 Firmware, Schneider-Electric Modicon M340 Bmx Noe 0100h Firmware, Schneider-Electric Modicon M340 Bmx Noe 0110 Firmware, Schneider-Electric Modicon M340 Bmx Noe 0110h Firmware, Schneider-Electric Modicon M340 Bmx nor 0200h Firmware, Schneider-Electric Modicon M340 Bmx P34-2010 Firmware, Schneider-Electric Modicon M340 Bmx P34-2030 Firmware, Schneider-Electric Modicon Quantum 140cpu65150 Firmware, Schneider-Electric Modicon Quantum 140cpu65150c Firmware, Schneider-Electric Modicon Quantum 140cpu65160 Firmware, Schneider-Electric Modicon Quantum 140cpu65160c Firmware, Schneider-Electric Modicon Quantum 140noc78100 Firmware, Schneider-Electric Modicon Quantum 140noe77101 Firmware, Schneider-Electric Modicon Quantum 140noe77111 Firmware, Schneider-Electric Modicon Tsxety4103 Firmware, Schneider-Electric Modicon Tsxety5103 Firmware, Schneider-Electric Modicon Tsxp574634 Firmware, Schneider-Electric Modicon Tsxp575634 Firmware, Schneider-Electric Modicon Tsxp576634 Firmware.

## How do I fix CVE-2020-7564?

No fix has been published for CVE-2020-7564 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-7564 being exploited?

There is no known exploitation of CVE-2020-7564 in the wild and no public exploit code.

## Other vulnerabilities in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details)

- [CVE-2020-7562](https://insights.sbomify.com/CVE-2020-7562/): Memory corruption in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details) (medium 6.3)
- [CVE-2020-7563](https://insights.sbomify.com/CVE-2020-7563/): Memory corruption in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details) (medium 6.3)
- [CVE-2013-2763](https://insights.sbomify.com/CVE-2013-2763/): Denial of service in n/a (medium 5.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-7564 and fix it if it is affected.

What it is: CVE-2020-7564 is a medium-severity memory corruption vulnerability in Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details), published on 18 Nov 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-7564 in the wild and no public exploit code.

Affected product: Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details). 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-2020-7564/ (Markdown: https://insights.sbomify.com/CVE-2020-7564/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-7564
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-7564
- OSV: https://osv.dev/vulnerability/CVE-2020-7564

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-7564/
Summaries are generated and may contain mistakes; the official description above is the record.