# CVE-2018-16558: Denial of service in SIMATIC S7-1500 CPU

> Unauthenticated remote attackers can cause a denial-of-service condition on Siemens SIMATIC S7-1500 CPUs via crafted network packets.

- **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:** 17 Apr 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-fc72-f69r-qvh3

## What is CVE-2018-16558?

CVE-2018-16558 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-1500 CPU, published on 17 Apr 2019. 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 S7-1500 CPU (All versions >= V2.0 and < V2.5), SIMATIC S7-1500 CPU (All versions <= V1.8.5). Specially crafted network packets sent to port 80/tcp or 443/tcp could allow an unauthenticated remote attacker to cause a Denial-of-Service condition of the device. The security vulnerability could be exploited by an attacker with network access to the affected systems on port 80/tcp or 443/tcp. Successful exploitation requires no system privileges and no user interaction. An attacker could use the vulnerability to compromise availability of the device. At the time of advisory publication no public exploitation of this security vulnerability was known.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2018-16558?

It affects 1 product.


Products: Siemens Simatic S7-1500 Firmware.

## How do I fix CVE-2018-16558?

No fix has been published for CVE-2018-16558 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-16558 being exploited?

There is no known exploitation of CVE-2018-16558 in the wild and no public exploit code.

## Other vulnerabilities in Siemens SIMATIC S7-1500 CPU

- [CVE-2018-16559](https://insights.sbomify.com/CVE-2018-16559/): Denial of service in SIMATIC S7-1500 CPU (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-16558 and fix it if it is affected.

What it is: CVE-2018-16558 is a high-severity denial of service vulnerability in Siemens SIMATIC S7-1500 CPU, published on 17 Apr 2019. 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-2018-16558 in the wild and no public exploit code.

Affected product: Siemens SIMATIC S7-1500 CPU. 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-2018-16558/ (Markdown: https://insights.sbomify.com/CVE-2018-16558/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-16558
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-16558
- OSV: https://osv.dev/vulnerability/CVE-2018-16558

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-16558/
Summaries are generated and may contain mistakes; the official description above is the record.