# CVE-2021-36226: Security feature bypass in n/a

> Attackers can install malicious firmware on Western Digital My Cloud devices due to missing cryptographic signatures, leading to full device compromise.

- **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:** 6 Feb 2023
- **Updated:** 26 Mar 2025
- **Also known as:** GHSA-wmmr-frfj-gmmw

## What is CVE-2021-36226?

CVE-2021-36226 is a critical vulnerability in n/a, published on 6 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Western Digital My Cloud devices before OS5 do not use cryptographically signed Firmware upgrade files.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2021-36226?

It affects 1 product.


Products: Westerndigital My Cloud Os.

## How do I fix CVE-2021-36226?

No fix has been published for CVE-2021-36226 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-36226 being exploited?

There is no known exploitation of CVE-2021-36226 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2023-22814](https://insights.sbomify.com/CVE-2023-22814/): Authentication Bypass issue in My Cloud OS 5 devices (critical 10.0)
- [CVE-2022-29842](https://insights.sbomify.com/CVE-2022-29842/): Command Injection Vulnerability in Western Digital My Cloud devices (critical 9.8)
- [CVE-2021-36224](https://insights.sbomify.com/CVE-2021-36224/): Hardcoded credentials in n/a (critical 9.8)
- [CVE-2022-22989](https://insights.sbomify.com/CVE-2022-22989/): Pre-authenticated stack overflow vulnerability on FTP Service (critical 9.8)
- [CVE-2021-36225](https://insights.sbomify.com/CVE-2021-36225/): Missing authorization in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-36226 and fix it if it is affected.

What it is: CVE-2021-36226 is a critical vulnerability in n/a, published on 6 Feb 2023. 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-2021-36226 in the wild and no public exploit code.

Affected product: n/a. 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-2021-36226/ (Markdown: https://insights.sbomify.com/CVE-2021-36226/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-36226
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-36226
- OSV: https://osv.dev/vulnerability/CVE-2021-36226

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-36226/
Summaries are generated and may contain mistakes; the official description above is the record.