# CVE-2018-8836: Denial of service in WAGO 750 Series

> Remote attackers can cause denial of service in WAGO 750 Series PLCs by sending crafted packets to port 2455, disrupting communication with service tools.

- **Severity:** Medium 5.3 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Apr 2018
- **Updated:** 17 Sep 2024
- **Also known as:** GHSA-pm5g-66xr-995q

## What is CVE-2018-8836?

CVE-2018-8836 is a medium-severity denial of service vulnerability in WAGO 750 Series, published on 3 Apr 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Wago 750 Series PLCs with firmware version 10 and prior include a remote attack may take advantage of an improper implementation of the 3 way handshake during a TCP connection affecting the communications with commission and service tools. Specially crafted packets may also be sent to Port 2455/TCP/IP, used in Codesys management software, which may result in a denial-of-service condition of communications with commissioning and service tools.

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

## Which versions are affected by CVE-2018-8836?

It affects 8 products.


Products: Wago 750-829 Firmware, Wago 750-831 Firmware, Wago 750-852 Firmware, Wago 750-880 Firmware, Wago 750-881 Firmware, Wago 750-882 Firmware, Wago 750-885 Firmware, Wago 750-889 Firmware.

## How do I fix CVE-2018-8836?

No fix has been published for CVE-2018-8836 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-8836 being exploited?

There is no known exploitation of CVE-2018-8836 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-8836 and fix it if it is affected.

What it is: CVE-2018-8836 is a medium-severity denial of service vulnerability in WAGO 750 Series, published on 3 Apr 2018. 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-2018-8836 in the wild and no public exploit code.

Affected product: WAGO 750 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-2018-8836/ (Markdown: https://insights.sbomify.com/CVE-2018-8836/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-8836
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-8836
- OSV: https://osv.dev/vulnerability/CVE-2018-8836

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-8836/
Summaries are generated and may contain mistakes; the official description above is the record.