# CVE-2018-20145: Missing authorization in n/a

> An ACL bypass in Eclipse Mosquitto allows unauthorized access when specific listener settings are enabled, requiring an upgrade to fix.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Dec 2018
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2018-20145, GHSA-p6fp-h8pq-3x5p

## What is CVE-2018-20145?

CVE-2018-20145 is a high-severity missing authorization vulnerability in n/a, published on 13 Dec 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Eclipse Mosquitto 1.5.x before 1.5.5 allows ACL bypass: if the option per_listener_settings was set to true, and the default listener was in use, and the default listener specified an acl_file, then the acl file was being ignored.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource)

## Which versions are affected by CVE-2018-20145?

It affects 1 product.


Products: Eclipse Mosquitto.

## How do I fix CVE-2018-20145?

Upgrade to a fixed version.

## Is CVE-2018-20145 being exploited?

There is no known exploitation of CVE-2018-20145 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2018-12550](https://insights.sbomify.com/CVE-2018-12550/): Auth bypass in Eclipse Mosquitto (high 8.1)
- [CVE-2018-12551](https://insights.sbomify.com/CVE-2018-12551/): Auth bypass in Eclipse Mosquitto (high 8.1)
- [CVE-2023-5632](https://insights.sbomify.com/CVE-2023-5632/): Unconditionally adding an event to the epoll causes excessive CPU consumption (high 7.5)
- [CVE-2023-28366](https://insights.sbomify.com/CVE-2023-28366/): Denial of service in n/a (high 7.5)
- [CVE-2021-41039](https://insights.sbomify.com/CVE-2021-41039/): Denial of service in Eclipse Mosquitto (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-20145 and fix it if it is affected.

What it is: CVE-2018-20145 is a high-severity missing authorization vulnerability in n/a, published on 13 Dec 2018. 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-2018-20145 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-2018-20145/ (Markdown: https://insights.sbomify.com/CVE-2018-20145/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-20145
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-20145
- OSV: https://osv.dev/vulnerability/CVE-2018-20145

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-20145/
Summaries are generated and may contain mistakes; the official description above is the record.