# CVE-2020-7502: Memory corruption in Modicon M218 Logic Controller (Firmware version 4.3 and prior)

> An out-of-bounds write vulnerability in the Modicon M218 Logic Controller allows attackers to cause a denial of service via crafted TCP/IP packets.

- **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:** 16 Jun 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-x4fw-v2f8-f3pj

## What is CVE-2020-7502?

CVE-2020-7502 is a high-severity memory corruption vulnerability in Modicon M218 Logic Controller (Firmware version 4.3 and prior), published on 16 Jun 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A CWE-787: Out-of-bounds Write vulnerability exists in Modicon M218 Logic Controller (Firmware version 4.3 and prior), which may cause a Denial of Service when specific TCP/IP crafted packets are sent to the Modicon M218 Logic Controller.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2020-7502?

It affects 1 product.


Products: Schneider-Electric Modicon M218 Firmware.

## How do I fix CVE-2020-7502?

No fix has been published for CVE-2020-7502 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-7502 being exploited?

There is no known exploitation of CVE-2020-7502 in the wild and no public exploit code.

## Other vulnerabilities in Modicon M218 Logic Controller (Firmware version 4.3 and prior)

- [CVE-2021-22800](https://insights.sbomify.com/CVE-2021-22800/): Denial of service in Modicon M218 Logic Controller (V5.1.0.6 and prior) (high 7.5)
- [CVE-2020-7524](https://insights.sbomify.com/CVE-2020-7524/): Memory corruption in Modicon M218 Logic Controller V5.0.0.7 and prior (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-7502 and fix it if it is affected.

What it is: CVE-2020-7502 is a high-severity memory corruption vulnerability in Modicon M218 Logic Controller (Firmware version 4.3 and prior), published on 16 Jun 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-2020-7502 in the wild and no public exploit code.

Affected product: Modicon M218 Logic Controller (Firmware version 4.3 and prior). 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-2020-7502/ (Markdown: https://insights.sbomify.com/CVE-2020-7502/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-7502
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-7502
- OSV: https://osv.dev/vulnerability/CVE-2020-7502

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-7502/
Summaries are generated and may contain mistakes; the official description above is the record.