# CVE-2020-10566: Memory corruption in n/a

> A buffer overflow in grub2-bhyve allows guest VMs to execute arbitrary code or escalate privileges on the host via a malicious configuration file.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 14 Mar 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-rj84-59vh-9hpj

## What is CVE-2020-10566?

CVE-2020-10566 is a high-severity memory corruption vulnerability in Freebsd Freebsd, published on 14 Mar 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

grub2-bhyve, as used in FreeBSD bhyve before revision 525916 2020-02-12, mishandles font loading by a guest through a grub2.cfg file, leading to a buffer overflow.

Weakness: CWE-120 (Buffer Copy without Checking Size of Input)

## Which versions are affected by CVE-2020-10566?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2020-10566?

No fix has been published for CVE-2020-10566 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-10566 being exploited?

There is no known exploitation of CVE-2020-10566 in the wild and no public exploit code.

## Other vulnerabilities in Freebsd Freebsd

- [CVE-2018-17160](https://insights.sbomify.com/CVE-2018-17160/): Memory corruption in FreeBSD (critical 10.0)
- [CVE-2014-3954](https://insights.sbomify.com/CVE-2014-3954/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-4304](https://insights.sbomify.com/CVE-2006-4304/): Memory corruption in n/a (critical 10.0)
- [CVE-2006-0226](https://insights.sbomify.com/CVE-2006-0226/): Integer overflow in n/a (critical 10.0)
- [CVE-2004-0002](https://insights.sbomify.com/CVE-2004-0002/): Denial of service in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-10566 and fix it if it is affected.

What it is: CVE-2020-10566 is a high-severity memory corruption vulnerability in Freebsd Freebsd, published on 14 Mar 2020. 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-2020-10566 in the wild and no public exploit code.

Affected product: Freebsd Freebsd. 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-2020-10566/ (Markdown: https://insights.sbomify.com/CVE-2020-10566/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-10566
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-10566
- OSV: https://osv.dev/vulnerability/CVE-2020-10566

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-10566/
Summaries are generated and may contain mistakes; the official description above is the record.