# CVE-2020-15783: Denial of service in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants)

> Attackers can cause a denial of service on Siemens industrial controllers by sending crafted packets, requiring a cold restart to recover.

- **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:** 12 Nov 2020
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-h3cm-r647-2vf6

## What is CVE-2020-15783?

CVE-2020-15783 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants), published on 12 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability has been identified in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (All versions), SIMATIC TDC CPU555 (All versions), SINUMERIK 840D sl (All versions). Sending multiple specially crafted packets to the affected devices could cause a Denial-of-Service on port 102. A cold restart is required to recover the service.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-15783?

It affects 12 products.


Products: Siemens Simatic S7-300 Cpu 312 Firmware, Siemens Simatic S7-300 Cpu 314 Firmware, Siemens Simatic S7-300 Cpu 315-2 Dp Firmware, Siemens Simatic S7-300 Cpu 315-2 Pn Firmware, Siemens Simatic S7-300 Cpu 315f-2 Dp Firmware, Siemens Simatic S7-300 Cpu 315f-2 Pn Firmware, Siemens Simatic S7-300 Cpu 317-2 Dp Firmware, Siemens Simatic S7-300 Cpu 317-2 Pn Firmware, Siemens Simatic S7-300 Cpu 317f-2 Dp Firmware, Siemens Simatic S7-300 Cpu 317f-2 Pn Firmware, Siemens Simatic Tdc Cpu555 Firmware, Siemens Sinumerik 840d Sl Firmware.

## How do I fix CVE-2020-15783?

No fix has been published for CVE-2020-15783 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-15783 being exploited?

There is no known exploitation of CVE-2020-15783 in the wild and no public exploit code.

## Other vulnerabilities in Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants)

- [CVE-2020-15791](https://insights.sbomify.com/CVE-2020-15791/): Information disclosure in SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants) (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-15783 and fix it if it is affected.

What it is: CVE-2020-15783 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants), published on 12 Nov 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-2020-15783 in the wild and no public exploit code.

Affected product: Siemens SIMATIC S7-300 CPU family (incl. related ET200 CPUs and SIPLUS variants). 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-2020-15783/ (Markdown: https://insights.sbomify.com/CVE-2020-15783/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-15783
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-15783
- OSV: https://osv.dev/vulnerability/CVE-2020-15783

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-15783/
Summaries are generated and may contain mistakes; the official description above is the record.