# CVE-2018-4854: Missing authorization in SICLOCK TC100, SICLOCK TC400

> An attacker can modify the administrative client on SICLOCK devices via TFTP, leading to code execution when users download and run the tampered file.

- **Severity:** High 8.8 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 3 Jul 2018
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-w4g7-qqm9-9hj6

## What is CVE-2018-4854?

CVE-2018-4854 is a high-severity missing authorization vulnerability in Siemens AG SICLOCK TC100, SICLOCK TC400, published on 3 Jul 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A vulnerability has been identified in SICLOCK TC100 (All versions) and SICLOCK TC400 (All versions). An attacker with network access to port 69/udp could modify the administrative client stored on the device. If a legitimate user downloads and executes the modified client from the affected device, then he/she could obtain code execution on the client system.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2018-4854?

It affects 2 products.


Products: Siemens Siclock Tc100 Firmware, Siemens Siclock Tc400 Firmware.

## How do I fix CVE-2018-4854?

No fix has been published for CVE-2018-4854 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-4854 being exploited?

There is no known exploitation of CVE-2018-4854 in the wild and no public exploit code.

## Other vulnerabilities in Siemens AG SICLOCK TC100, SICLOCK TC400

- [CVE-2018-4852](https://insights.sbomify.com/CVE-2018-4852/): Auth bypass in SICLOCK TC100, SICLOCK TC400 (critical 9.8)
- [CVE-2018-4853](https://insights.sbomify.com/CVE-2018-4853/): Missing authorization in SICLOCK TC100, SICLOCK TC400 (critical 9.8)
- [CVE-2018-4851](https://insights.sbomify.com/CVE-2018-4851/): Denial of service in SICLOCK TC100, SICLOCK TC400 (high 8.2)
- [CVE-2018-4855](https://insights.sbomify.com/CVE-2018-4855/): Information disclosure in SICLOCK TC100, SICLOCK TC400 (medium 6.5)
- [CVE-2018-4856](https://insights.sbomify.com/CVE-2018-4856/): Auth bypass in SICLOCK TC100, SICLOCK TC400 (medium 4.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-4854 and fix it if it is affected.

What it is: CVE-2018-4854 is a high-severity missing authorization vulnerability in Siemens AG SICLOCK TC100, SICLOCK TC400, published on 3 Jul 2018. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2018-4854 in the wild and no public exploit code.

Affected product: Siemens AG SICLOCK TC100, SICLOCK TC400. 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-2018-4854/ (Markdown: https://insights.sbomify.com/CVE-2018-4854/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-4854
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-4854
- OSV: https://osv.dev/vulnerability/CVE-2018-4854

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From sbomify Insights: https://insights.sbomify.com/CVE-2018-4854/
Summaries are generated and may contain mistakes; the official description above is the record.