# CVE-2021-4161: ICSA-21-357-01 Moxa MGate Protocol Gateways

> Attackers can sniff traffic to decrypt credentials and gain admin access on Moxa MGate protocol gateways due to weak cryptography.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/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:** Not needed
- **Fix available:** No
- **Published:** 27 Dec 2021
- **Updated:** 16 Sep 2024
- **Also known as:** GHSA-628p-46mw-v4f9

## What is CVE-2021-4161?

CVE-2021-4161 is a critical vulnerability in Moxa MGate MB3180 Series, published on 27 Dec 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The affected products contain vulnerable firmware, which could allow an attacker to sniff the traffic and decrypt login credential details. This could give an attacker admin rights through the HTTP web server.

Weakness: CWE-319 (Cleartext Transmission of Sensitive Information)

## Which versions are affected by CVE-2021-4161?

It affects 3 products.


Products: Moxa Mgate Mb3180 Firmware, Moxa Mgate Mb3280 Firmware, Moxa Mgate Mb3480 Firmware.

## How do I fix CVE-2021-4161?

No fix has been published for CVE-2021-4161 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-4161 being exploited?

There is no known exploitation of CVE-2021-4161 in the wild and no public exploit code.

## Other vulnerabilities in Moxa MGate MB3180 Series

- [CVE-2021-33823](https://insights.sbomify.com/CVE-2021-33823/): Denial of service in n/a (high 7.5)
- [CVE-2021-33824](https://insights.sbomify.com/CVE-2021-33824/): Denial of service in n/a (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-4161 and fix it if it is affected.

What it is: CVE-2021-4161 is a critical vulnerability in Moxa MGate MB3180 Series, published on 27 Dec 2021. 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-2021-4161 in the wild and no public exploit code.

Affected product: Moxa MGate MB3180 Series. 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-2021-4161/ (Markdown: https://insights.sbomify.com/CVE-2021-4161/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-4161
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-4161
- OSV: https://osv.dev/vulnerability/CVE-2021-4161

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-4161/
Summaries are generated and may contain mistakes; the official description above is the record.