# CVE-2020-6991: Weak cryptography in Moxa EDS-G516E Series firmware, Version 5.2 or lower

> Weak password requirements in Moxa EDS-G516E firmware allow attackers to gain unauthorized access via brute force attacks.

- **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:** 24 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-hxmj-c6q3-rm4g

## What is CVE-2020-6991?

CVE-2020-6991 is a critical vulnerability in Moxa EDS-G516E Series firmware, Version 5.2 or lower, published on 24 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In Moxa EDS-G516E Series firmware, Version 5.2 or lower, weak password requirements may allow an attacker to gain access using brute force.

Weakness: CWE-521 (Weak Password Requirements)

## Which versions are affected by CVE-2020-6991?

It affects 2 products.


Products: Moxa Eds-510e Firmware, Moxa Eds-G516e Firmware.

## How do I fix CVE-2020-6991?

No fix has been published for CVE-2020-6991 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-6991 being exploited?

There is no known exploitation of CVE-2020-6991 in the wild and no public exploit code.

## Other vulnerabilities in Moxa EDS-G516E Series firmware, Version 5.2 or lower

- [CVE-2020-6981](https://insights.sbomify.com/CVE-2020-6981/): Hardcoded credentials in Moxa EDS-G516E Series firmware, Version 5.2 or lower (critical 9.8)
- [CVE-2020-7007](https://insights.sbomify.com/CVE-2020-7007/): Memory corruption in Moxa EDS-G516E Series firmware, Version 5.2 or lower (critical 9.8)
- [CVE-2020-6979](https://insights.sbomify.com/CVE-2020-6979/): Hardcoded credentials in Moxa EDS-G516E Series firmware, Version 5.2 or lower (high 7.5)
- [CVE-2020-6997](https://insights.sbomify.com/CVE-2020-6997/): Information disclosure in Moxa EDS-G516E Series firmware, Version 5.2 or lower (high 7.5)
- [CVE-2020-7001](https://insights.sbomify.com/CVE-2020-7001/): Weak cryptography in Moxa EDS-G516E Series firmware, Version 5.2 or lower (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-6991 and fix it if it is affected.

What it is: CVE-2020-6991 is a critical vulnerability in Moxa EDS-G516E Series firmware, Version 5.2 or lower, published on 24 Mar 2020. 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-2020-6991 in the wild and no public exploit code.

Affected product: Moxa EDS-G516E Series firmware, Version 5.2 or lower. 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-2020-6991/ (Markdown: https://insights.sbomify.com/CVE-2020-6991/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-6991
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-6991
- OSV: https://osv.dev/vulnerability/CVE-2020-6991

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-6991/
Summaries are generated and may contain mistakes; the official description above is the record.