# CVE-2021-21194: Use after free in Chrome

> A remote attacker can exploit heap corruption via a crafted HTML page due to a use-after-free in Chrome's screen sharing feature.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 9 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** CLEANSTART-2024-ZF25345, DEBIAN-CVE-2021-21194, GHSA-2qv4-c5gv-5f74, UBUNTU-CVE-2021-21194

## What is CVE-2021-21194?

CVE-2021-21194 is a high-severity use after free vulnerability in Fedoraproject Fedora, published on 9 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Use after free in screen sharing in Google Chrome prior to 89.0.4389.114 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2021-21194?

It affects 2 products.


Products: Fedoraproject Fedora, Google Chrome.

## How do I fix CVE-2021-21194?

Upgrade to a fixed version.

## Is CVE-2021-21194 being exploited?

There is no known exploitation of CVE-2021-21194 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21194 and fix it if it is affected.

What it is: CVE-2021-21194 is a high-severity use after free vulnerability in Fedoraproject Fedora, published on 9 Apr 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-21194 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2021-21194/ (Markdown: https://insights.sbomify.com/CVE-2021-21194/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21194
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21194
- OSV: https://osv.dev/vulnerability/CVE-2021-21194

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21194/
Summaries are generated and may contain mistakes; the official description above is the record.