# CVE-2021-42851: Missing authorization in Personal Cloud Storage A1

> Unauthenticated attackers can create standard user accounts on Lenovo Personal Cloud Storage devices, potentially leading to unauthorized access.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`)
- **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:** 18 May 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-r4g7-77xq-h6p2

## What is CVE-2021-42851?

CVE-2021-42851 is a medium-severity missing authorization vulnerability in Lenovo Personal Cloud Storage A1, published on 18 May 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was reported in some Lenovo Personal Cloud Storage devices that could allow an unauthenticated user to create a standard user account.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2021-42851?

It affects 5 products.


Products: Lenovo A1 Firmware, Lenovo T1 Firmware, Lenovo T2 Firmware, Lenovo T2pro Firmware, Lenovo X1 Firmware.

## How do I fix CVE-2021-42851?

No fix has been published for CVE-2021-42851 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42851 being exploited?

There is no known exploitation of CVE-2021-42851 in the wild and no public exploit code.

## Other vulnerabilities in Lenovo Personal Cloud Storage A1

- [CVE-2021-42850](https://insights.sbomify.com/CVE-2021-42850/): Hardcoded credentials in Personal Cloud Storage A1 (high 8.8)
- [CVE-2021-42852](https://insights.sbomify.com/CVE-2021-42852/): Command injection in Personal Cloud Storage A1 (high 8.0)
- [CVE-2021-42849](https://insights.sbomify.com/CVE-2021-42849/): Hardcoded credentials in Personal Cloud Storage A1 (medium 6.8)
- [CVE-2021-42848](https://insights.sbomify.com/CVE-2021-42848/): Information disclosure in Personal Cloud Storage A1 (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42851 and fix it if it is affected.

What it is: CVE-2021-42851 is a medium-severity missing authorization vulnerability in Lenovo Personal Cloud Storage A1, published on 18 May 2022. 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-2021-42851 in the wild and no public exploit code.

Affected product: Lenovo Personal Cloud Storage A1. 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-2021-42851/ (Markdown: https://insights.sbomify.com/CVE-2021-42851/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42851
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42851
- OSV: https://osv.dev/vulnerability/CVE-2021-42851

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42851/
Summaries are generated and may contain mistakes; the official description above is the record.