# CVE-2017-9938: Denial of service in SIMATIC Logon All versions before V1.6

> Attackers can cause a denial-of-service condition in Siemens SIMATIC Logon by sending specially crafted packets to the remote access service.

- **Severity:** High 7.5 (`CVSS:3.0/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:** 8 Aug 2017
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-gr6m-h2q8-p89j

## What is CVE-2017-9938?

CVE-2017-9938 is a high-severity denial of service vulnerability in SIMATIC Logon All versions before V1.6, published on 8 Aug 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was discovered in Siemens SIMATIC Logon (All versions before V1.6) that could allow specially crafted packets sent to the SIMATIC Logon Remote Access service on port 16389/tcp to cause a Denial-of-Service condition. The service restarts automatically.

Weakness: CWE-20 (Improper Input Validation), CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2017-9938?

It affects 1 product.


Products: Siemens Simatic Logon.

## How do I fix CVE-2017-9938?

No fix has been published for CVE-2017-9938 yet. Limit exposure of the affected software until one is available.

## Is CVE-2017-9938 being exploited?

There is no known exploitation of CVE-2017-9938 in the wild and no public exploit code.

## Other vulnerabilities in SIMATIC Logon All versions before V1.6

- [CVE-2017-2684](https://insights.sbomify.com/CVE-2017-2684/): Auth bypass in SIMATIC Logon All versions < V1.5 SP3 Update 2 (critical 9.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-9938 and fix it if it is affected.

What it is: CVE-2017-9938 is a high-severity denial of service vulnerability in SIMATIC Logon All versions before V1.6, published on 8 Aug 2017. 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-2017-9938 in the wild and no public exploit code.

Affected product: SIMATIC Logon All versions before V1.6. 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-2017-9938/ (Markdown: https://insights.sbomify.com/CVE-2017-9938/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-9938
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-9938
- OSV: https://osv.dev/vulnerability/CVE-2017-9938

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From sbomify Insights: https://insights.sbomify.com/CVE-2017-9938/
Summaries are generated and may contain mistakes; the official description above is the record.