# CVE-2018-18931: Privilege escalation in n/a

> An attacker with local access can escalate privileges to SYSTEM by replacing a service executable due to insecure default directory permissions.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-989h-pjm5-xvqg

## What is CVE-2018-18931?

CVE-2018-18931 is a high-severity vulnerability in n/a, published on 29 Oct 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An issue was discovered in the Tightrope Media Carousel digital signage product 7.0.4.104. Due to insecure default permissions on the C:\TRMS\Services directory, an attacker who has gained access to the system can elevate their privileges from a restricted account to full SYSTEM by replacing the Carousel.Service.exe file with a custom malicious executable. This service is independent of the associated IIS web site, which means that this service can be manipulated by an attacker without losing access to vulnerabilities in the web interface (which would potentially be used in conjunction with this attack, to control the service). Once the attacker has replaced Carousel.Service.exe, the server can be restarted using the command "shutdown -r -t 0" from a web shell, causing the system to reboot and launching the malicious Carousel.Service.exe as SYSTEM on startup. If this malicious Carousel.Service.exe is configured to launch a reverse shell back to the attacker, then upon reboot the attacker will have a fully privileged remote command-line environment to manipulate the system further.

Weakness: CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2018-18931?

It affects 1 product.


Products: Trms Carousel Digital Signage.

## How do I fix CVE-2018-18931?

No fix has been published for CVE-2018-18931 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-18931 being exploited?

There is no known exploitation of CVE-2018-18931 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-18930](https://insights.sbomify.com/CVE-2018-18930/): File upload in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-18931 and fix it if it is affected.

What it is: CVE-2018-18931 is a high-severity vulnerability in n/a, published on 29 Oct 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2018-18931 in the wild and no public exploit code.

Affected product: n/a. 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-2018-18931/ (Markdown: https://insights.sbomify.com/CVE-2018-18931/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-18931
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-18931
- OSV: https://osv.dev/vulnerability/CVE-2018-18931

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-18931/
Summaries are generated and may contain mistakes; the official description above is the record.