# CVE-2021-3721: Denial of service in PCManager

> A local attacker can trigger a blue screen error in Lenovo PCManager, causing a denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Apr 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-j8c3-7w65-qf2g

## What is CVE-2021-3721?

CVE-2021-3721 is a medium-severity denial of service vulnerability in Lenovo PCManager, published on 22 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A denial of service vulnerability was reported in Lenovo PCManager prior to version 4.0.20.10282 that could allow an attacker with local access to trigger a blue screen error.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2021-3721?

It affects 1 product.


Products: Lenovo Pcmanager.

## How do I fix CVE-2021-3721?

No fix has been published for CVE-2021-3721 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3721 being exploited?

There is no known exploitation of CVE-2021-3721 in the wild and no public exploit code.

## Other vulnerabilities in Lenovo PCManager

- [CVE-2025-10581](https://insights.sbomify.com/CVE-2025-10581/): Privilege escalation in PC Manager (high 8.5)
- [CVE-2025-8486](https://insights.sbomify.com/CVE-2025-8486/): Privilege escalation in PC Manager (high 8.5)
- [CVE-2025-8098](https://insights.sbomify.com/CVE-2025-8098/): Privilege escalation in PC Manager (high 8.5)
- [CVE-2025-2501](https://insights.sbomify.com/CVE-2025-2501/): Privilege escalation in PC Manager (high 8.5)
- [CVE-2025-2502](https://insights.sbomify.com/CVE-2025-2502/): Privilege escalation in PC Manager (high 8.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3721 and fix it if it is affected.

What it is: CVE-2021-3721 is a medium-severity denial of service vulnerability in Lenovo PCManager, published on 22 Apr 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-2021-3721 in the wild and no public exploit code.

Affected product: Lenovo PCManager. 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-2021-3721/ (Markdown: https://insights.sbomify.com/CVE-2021-3721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3721
- OSV: https://osv.dev/vulnerability/CVE-2021-3721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3721/
Summaries are generated and may contain mistakes; the official description above is the record.