# CVE-2018-7758: Denial of service in MiCOM P540D Range with Legacy Ethernet Board

> An attacker can cause loss of network communication in Schneider Electric MiCOM relays by exploiting TCP/IP session handling flaws on port 20000.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:A/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Apr 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-w8w3-m5jx-qwwr

## What is CVE-2018-7758?

CVE-2018-7758 is a medium-severity denial of service vulnerability in Schneider Electric SE MiCOM P540D Range with Legacy Ethernet Board, published on 18 Apr 2018. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A denial of service vulnerability exists in Schneider Electric's MiCOM Px4x (P540 range excluded) with legacy Ethernet board, MiCOM P540D Range with Legacy Ethernet Board, and MiCOM Px4x Rejuvenated could lose network communication in case of TCP/IP open requests on port 20000 (DNP3oE) if an older TCI/IP session is still open with identical IP address and port number.

Weakness: CWE-613 (DEPRECATED: Insufficient Session Expiration)

## Which versions are affected by CVE-2018-7758?

It affects 23 products.


Products: Schneider-Electric Micom P141 Firmware, Schneider-Electric Micom P142 Firmware, Schneider-Electric Micom P143 Firmware, Schneider-Electric Micom P145 Firmware, Schneider-Electric Micom P441 Firmware, Schneider-Electric Micom P442 Firmware, Schneider-Electric Micom P443 Firmware, Schneider-Electric Micom P444 Firmware, Schneider-Electric Micom P445 Firmware, Schneider-Electric Micom P446 Firmware, Schneider-Electric Micom P541 Firmware, Schneider-Electric Micom P542 Firmware, Schneider-Electric Micom P543 Firmware, Schneider-Electric Micom P544 Firmware, Schneider-Electric Micom P545 Firmware, Schneider-Electric Micom P546 Firmware, Schneider-Electric Micom P642 Firmware, Schneider-Electric Micom P643 Firmware, Schneider-Electric Micom P645 Firmware, Schneider-Electric Micom P746 Firmware and 3 more.

## How do I fix CVE-2018-7758?

No fix has been published for CVE-2018-7758 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-7758 being exploited?

There is no known exploitation of CVE-2018-7758 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-7758 and fix it if it is affected.

What it is: CVE-2018-7758 is a medium-severity denial of service vulnerability in Schneider Electric SE MiCOM P540D Range with Legacy Ethernet Board, published on 18 Apr 2018. 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-2018-7758 in the wild and no public exploit code.

Affected product: Schneider Electric SE MiCOM P540D Range with Legacy Ethernet Board. 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-2018-7758/ (Markdown: https://insights.sbomify.com/CVE-2018-7758/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-7758
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-7758
- OSV: https://osv.dev/vulnerability/CVE-2018-7758

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-7758/
Summaries are generated and may contain mistakes; the official description above is the record.