# CVE-2021-34571: Hard-coded Credentials in Enbra Wireless M-Bus devices

> Attackers can access sensitive data from Enbra Wireless M-Bus devices due to hard-coded credentials in Security mode 5.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Sep 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-mmrg-jwv9-9h53

## What is CVE-2021-34571?

CVE-2021-34571 is a medium-severity vulnerability in Enbra AT-WMBUS-16-2, published on 16 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Multiple Wireless M-Bus devices by Enbra use Hard-coded Credentials in Security mode 5 without an option to change the encryption key. An adversary can learn all information that is available in Enbra EWM.

Weakness: CWE-798 (Use of Hard-coded Credentials)

## Which versions are affected by CVE-2021-34571?

It affects 1 product.


Products: Enbra Ewm.

## How do I fix CVE-2021-34571?

No fix has been published for CVE-2021-34571 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34571 being exploited?

There is no known exploitation of CVE-2021-34571 in the wild and no public exploit code.

## Other vulnerabilities in Enbra AT-WMBUS-16-2

- [CVE-2021-34572](https://insights.sbomify.com/CVE-2021-34572/): Insufficient Verification of Data Authenticity in Enbra EWM (replay attack) (medium 6.5)
- [CVE-2021-34573](https://insights.sbomify.com/CVE-2021-34573/): Incorrect calculation in Enbra EWM does not report backflows or no flow events (medium 6.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-34571 and fix it if it is affected.

What it is: CVE-2021-34571 is a medium-severity vulnerability in Enbra AT-WMBUS-16-2, published on 16 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-34571 in the wild and no public exploit code.

Affected product: Enbra AT-WMBUS-16-2. 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-2021-34571/ (Markdown: https://insights.sbomify.com/CVE-2021-34571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34571
- OSV: https://osv.dev/vulnerability/CVE-2021-34571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-34571/
Summaries are generated and may contain mistakes; the official description above is the record.