# CVE-2024-43647: Denial of service in SIMATIC S7-200 SMART CPU CR40

> Unauthenticated remote attackers can cause a denial of service on Siemens SIMATIC S7-200 SMART PLCs by sending malformed TCP packets, requiring physical cable reconnection to recover.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Sep 2024
- **Updated:** 10 Sep 2024
- **Also known as:** GHSA-6x28-mpjc-6r6h

## What is CVE-2024-43647?

CVE-2024-43647 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-200 SMART CPU CR40, published on 10 Sep 2024. 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 S7-200 SMART CPU CR40 (6ES7288-1CR40-0AA0) (All versions), SIMATIC S7-200 SMART CPU CR60 (6ES7288-1CR60-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR20 (6ES7288-1SR20-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR20 (6ES7288-1SR20-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR30 (6ES7288-1SR30-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR30 (6ES7288-1SR30-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR40 (6ES7288-1SR40-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR40 (6ES7288-1SR40-0AA1) (All versions), SIMATIC S7-200 SMART CPU SR60 (6ES7288-1SR60-0AA0) (All versions), SIMATIC S7-200 SMART CPU SR60 (6ES7288-1SR60-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST20 (6ES7288-1ST20-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST20 (6ES7288-1ST20-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST30 (6ES7288-1ST30-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST30 (6ES7288-1ST30-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST40 (6ES7288-1ST40-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST40 (6ES7288-1ST40-0AA1) (All versions), SIMATIC S7-200 SMART CPU ST60 (6ES7288-1ST60-0AA0) (All versions), SIMATIC S7-200 SMART CPU ST60 (6ES7288-1ST60-0AA1) (All versions). Affected devices do not properly handle TCP packets with an incorrect structure. This could allow an unauthenticated remote attacker to cause a denial of service condition. To restore normal operations, the network cable of the device needs to be unplugged and re-plugged.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2024-43647?


## How do I fix CVE-2024-43647?

No fix has been published for CVE-2024-43647 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-43647 being exploited?

There is no known exploitation of CVE-2024-43647 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-43647 and fix it if it is affected.

What it is: CVE-2024-43647 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-200 SMART CPU CR40, published on 10 Sep 2024. 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-2024-43647 in the wild and no public exploit code.

Affected product: Siemens SIMATIC S7-200 SMART CPU CR40. 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-2024-43647/ (Markdown: https://insights.sbomify.com/CVE-2024-43647/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43647
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43647
- OSV: https://osv.dev/vulnerability/CVE-2024-43647

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From sbomify Insights: https://insights.sbomify.com/CVE-2024-43647/
Summaries are generated and may contain mistakes; the official description above is the record.