# CVE-2020-28214: Weak cryptography in Modicon M221 (all references, all versions)

> Attackers can pre-compute password hashes using rainbow tables due to predictable salts, bypassing authentication protections in Modicon M221 devices.

- **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:** 11 Dec 2020
- **Updated:** 28 May 2026
- **Also known as:** GHSA-w259-g563-xw2j

## What is CVE-2020-28214?

CVE-2020-28214 is a critical vulnerability in Modicon M221 (all references, all versions), published on 11 Dec 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A CWE-760: Use of a One-Way Hash with a Predictable Salt vulnerability exists in Modicon M221 (all references, all versions), that could allow an attacker to pre-compute the hash value using dictionary attack technique such as rainbow tables, effectively disabling the protection that an unpredictable salt would provide.

Weakness: CWE-760 (Use of a One-Way Hash with a Predictable Salt)

## Which versions are affected by CVE-2020-28214?

It affects 1 product.


Products: Schneider-Electric Modicon M221 Firmware.

## How do I fix CVE-2020-28214?

No fix has been published for CVE-2020-28214 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-28214 being exploited?

There is no known exploitation of CVE-2020-28214 in the wild and no public exploit code.

## Other vulnerabilities in Modicon M221 (all references, all versions)

- [CVE-2018-7790](https://insights.sbomify.com/CVE-2018-7790/): Auth bypass in Modicon M221, all references, all versions prior to firmware V1.6.2.0 (critical 9.8)
- [CVE-2018-7791](https://insights.sbomify.com/CVE-2018-7791/): Auth bypass in Modicon M221, all references, all versions prior to firmware V1.6.2.0 (critical 9.8)
- [CVE-2018-7821](https://insights.sbomify.com/CVE-2018-7821/): Denial of service in SoMachine Basic and Modicon M221, SoMachine Basic, all versions Modicon M221, all references, all versions prior to firmware V1.10.0.0 (high 7.5)
- [CVE-2018-7792](https://insights.sbomify.com/CVE-2018-7792/): Weak cryptography in Modicon M221, all references, all versions prior to firmware V1.6.2.0 (high 7.5)
- [CVE-2020-7565](https://insights.sbomify.com/CVE-2020-7565/): Weak cryptography in Modicon M221, all references, all versions (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-28214 and fix it if it is affected.

What it is: CVE-2020-28214 is a critical vulnerability in Modicon M221 (all references, all versions), published on 11 Dec 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-2020-28214 in the wild and no public exploit code.

Affected product: Modicon M221 (all references, all versions). 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-2020-28214/ (Markdown: https://insights.sbomify.com/CVE-2020-28214/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-28214
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-28214
- OSV: https://osv.dev/vulnerability/CVE-2020-28214

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-28214/
Summaries are generated and may contain mistakes; the official description above is the record.