# CVE-2023-35921: Denial of service in SIMATIC MV540 H

> Unauthenticated remote attackers can cause a denial of service on Siemens SIMATIC vision sensors by sending crafted Ethernet frames, requiring manual restarts.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 Jul 2023
- **Updated:** 13 Nov 2024
- **Also known as:** GHSA-8m33-v7qf-p597

## What is CVE-2023-35921?

CVE-2023-35921 is a high-severity denial of service vulnerability in Siemens SIMATIC MV540 H, published on 11 Jul 2023. 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 MV540 H (All versions < V3.3.4), SIMATIC MV540 S (All versions < V3.3.4), SIMATIC MV550 H (All versions < V3.3.4), SIMATIC MV550 S (All versions < V3.3.4), SIMATIC MV560 U (All versions < V3.3.4), SIMATIC MV560 X (All versions < V3.3.4). Affected devices cannot properly process specially crafted Ethernet frames sent to the devices. This could allow an unauthenticated remote attacker to cause a denial of service condition. The affected devices must be restarted manually.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2023-35921?

It affects 6 products.


Products: Siemens Simatic Mv540 H Firmware, Siemens Simatic Mv540 S Firmware, Siemens Simatic Mv550 H Firmware, Siemens Simatic Mv550 S Firmware, Siemens Simatic Mv560 U Firmware, Siemens Simatic Mv560 X Firmware.

## How do I fix CVE-2023-35921?

No fix has been published for CVE-2023-35921 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-35921 being exploited?

There is no known exploitation of CVE-2023-35921 in the wild and no public exploit code.

## Other vulnerabilities in Siemens SIMATIC MV540 H

- [CVE-2023-36521](https://insights.sbomify.com/CVE-2023-36521/): Denial of service in SIMATIC MV540 H (high 8.6)
- [CVE-2022-33137](https://insights.sbomify.com/CVE-2022-33137/): Auth bypass in SIMATIC MV540 H (high 8.0)
- [CVE-2023-35920](https://insights.sbomify.com/CVE-2023-35920/): Denial of service in SIMATIC MV540 H (high 7.5)
- [CVE-2022-33138](https://insights.sbomify.com/CVE-2022-33138/): Missing authorization in SIMATIC MV540 H (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-35921 and fix it if it is affected.

What it is: CVE-2023-35921 is a high-severity denial of service vulnerability in Siemens SIMATIC MV540 H, published on 11 Jul 2023. 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-2023-35921 in the wild and no public exploit code.

Affected product: Siemens SIMATIC MV540 H. 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-2023-35921/ (Markdown: https://insights.sbomify.com/CVE-2023-35921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-35921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-35921
- OSV: https://osv.dev/vulnerability/CVE-2023-35921

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From sbomify Insights: https://insights.sbomify.com/CVE-2023-35921/
Summaries are generated and may contain mistakes; the official description above is the record.