# CVE-2021-36979: Memory corruption in n/a

> An out-of-bounds write in Unicorn Engine allows attackers to execute arbitrary code or cause denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 20 Jul 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-65p9-86g3-vxrx

## What is CVE-2021-36979?

CVE-2021-36979 is a medium-severity memory corruption vulnerability in Fedoraproject Fedora, published on 20 Jul 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Unicorn Engine 1.0.2 has an out-of-bounds write in tb_flush_armeb (called from cpu_arm_exec_armeb and tcg_cpu_exec_armeb).

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

## Which versions are affected by CVE-2021-36979?

It affects 2 products.


Products: Fedoraproject Fedora, Unicorn-Engine Unicorn Engine.

## How do I fix CVE-2021-36979?

No fix has been published for CVE-2021-36979 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-36979 being exploited?

There is no known exploitation of CVE-2021-36979 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-2021-36979 and fix it if it is affected.

What it is: CVE-2021-36979 is a medium-severity memory corruption vulnerability in Fedoraproject Fedora, published on 20 Jul 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-36979 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-2021-36979/ (Markdown: https://insights.sbomify.com/CVE-2021-36979/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-36979
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-36979
- OSV: https://osv.dev/vulnerability/CVE-2021-36979

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-36979/
Summaries are generated and may contain mistakes; the official description above is the record.