# CVE-2021-3982: Privilege escalation in gnome-shell

> Low-privilege attackers can exploit CAP_SYS_NICE in gnome-shell to escalate privileges and cause denial of service on Linux systems.

- **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:** Yes
- **Published:** 29 Apr 2022
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-w69m-w3gr-72pp, MGASA-2022-0007, UBUNTU-CVE-2021-3982

## What is CVE-2021-3982?

CVE-2021-3982 is a medium-severity vulnerability in gnome-shell, published on 29 Apr 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Linux distributions using CAP_SYS_NICE for gnome-shell may be exposed to a privilege escalation issue. An attacker, with low privilege permissions, may take advantage of the way CAP_SYS_NICE is currently implemented and eventually load code to increase its process scheduler priority leading to possible DoS of other services running in the same machine.

Weakness: CWE-273 (Improper Check for Dropped Privileges)

## Which versions are affected by CVE-2021-3982?

It affects 1 product.


Products: Gnome Gnome-Shell.

## How do I fix CVE-2021-3982?

Apply the vendor's patch.

## Is CVE-2021-3982 being exploited?

There is no known exploitation of CVE-2021-3982 in the wild and no public exploit code.

## Other vulnerabilities in gnome-shell

- [CVE-2017-8288](https://insights.sbomify.com/CVE-2017-8288/): Security feature bypass in n/a (high 8.1)
- [CVE-2014-7300](https://insights.sbomify.com/CVE-2014-7300/): Denial of service in n/a (high 7.2)
- [CVE-2010-4000](https://insights.sbomify.com/CVE-2010-4000/): Privilege escalation in n/a (medium 6.9)
- [CVE-2012-4427](https://insights.sbomify.com/CVE-2012-4427/): Code injection in n/a (medium 6.8)
- [CVE-2013-7220](https://insights.sbomify.com/CVE-2013-7220/): Command injection in n/a (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3982 and fix it if it is affected.

What it is: CVE-2021-3982 is a medium-severity vulnerability in gnome-shell, published on 29 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-2021-3982 in the wild and no public exploit code.

Affected product: gnome-shell. 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-2021-3982/ (Markdown: https://insights.sbomify.com/CVE-2021-3982/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3982
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3982
- OSV: https://osv.dev/vulnerability/CVE-2021-3982

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3982/
Summaries are generated and may contain mistakes; the official description above is the record.