# CVE-2021-37199: Memory corruption in SINUMERIK 808D

> An attacker can cause a denial-of-service on Siemens SINUMERIK CNC controllers by sending crafted packets to port 102/tcp.

- **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 Oct 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-q6gp-rmpv-2ghj

## What is CVE-2021-37199?

CVE-2021-37199 is a high-severity memory corruption vulnerability in Siemens SINUMERIK 808D, published on 12 Oct 2021. 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 SINUMERIK 808D (All versions), SINUMERIK 828D (All versions < V4.95). Affected devices don't process correctly certain special crafted packets sent to port 102/tcp, which could allow an attacker to cause a denial-of-service in the device.

Weakness: CWE-787 (Out-of-bounds Write), CWE-122 (Heap-based Buffer Overflow)

## Which versions are affected by CVE-2021-37199?

It affects 2 products.


Products: Siemens Sinumerik 808d Firmware, Siemens Sinumerik 828d Firmware.

## How do I fix CVE-2021-37199?

No fix has been published for CVE-2021-37199 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-37199 being exploited?

There is no known exploitation of CVE-2021-37199 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-37199 and fix it if it is affected.

What it is: CVE-2021-37199 is a high-severity memory corruption vulnerability in Siemens SINUMERIK 808D, published on 12 Oct 2021. 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-2021-37199 in the wild and no public exploit code.

Affected product: Siemens SINUMERIK 808D. 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-2021-37199/ (Markdown: https://insights.sbomify.com/CVE-2021-37199/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-37199
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-37199
- OSV: https://osv.dev/vulnerability/CVE-2021-37199

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-37199/
Summaries are generated and may contain mistakes; the official description above is the record.