# CVE-2021-34572: Insufficient Verification of Data Authenticity in Enbra EWM (replay attack)

> Attackers can replay wireless M-Bus sensor data because the system fails to detect replays, leading to inaccurate readings.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/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:** 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-7x8j-m6q2-x954

## What is CVE-2021-34572?

CVE-2021-34572 is a medium-severity vulnerability in Enbra EWM 1.7.29, 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

Enbra EWM 1.7.29 does not check for or detect replay attacks sent by wireless M-Bus Security mode 5 devices. Instead timestamps of the sensor are replaced by the time of the readout even if the data is a replay of earlier data.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity)

## Which versions are affected by CVE-2021-34572?

It affects 1 product.


Products: Enbra Ewm.

## How do I fix CVE-2021-34572?

No fix has been published for CVE-2021-34572 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-34572 being exploited?

There is no known exploitation of CVE-2021-34572 in the wild and no public exploit code.

## Other vulnerabilities in Enbra EWM 1.7.29

- [CVE-2021-34571](https://insights.sbomify.com/CVE-2021-34571/): Hard-coded Credentials in Enbra Wireless M-Bus devices (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-2021-34572 and fix it if it is affected.

What it is: CVE-2021-34572 is a medium-severity vulnerability in Enbra EWM 1.7.29, 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-2021-34572 in the wild and no public exploit code.

Affected product: Enbra EWM 1.7.29. 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-2021-34572/ (Markdown: https://insights.sbomify.com/CVE-2021-34572/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-34572
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-34572
- OSV: https://osv.dev/vulnerability/CVE-2021-34572

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-34572/
Summaries are generated and may contain mistakes; the official description above is the record.