# CVE-2020-25584: Race condition in FreeBSD

> A superuser in a FreeBSD jail with non-default mount permissions can exploit a race condition to escape the jail and access the host filesystem.

- **Severity:** High 7.5 (`CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Apr 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-54rh-2mjp-cvmq

## What is CVE-2020-25584?

CVE-2020-25584 is a high-severity vulnerability in Freebsd Freebsd, published on 7 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In FreeBSD 13.0-STABLE before n245118, 12.2-STABLE before r369552, 11.4-STABLE before r369560, 13.0-RC5 before p1, 12.2-RELEASE before p6, and 11.4-RELEASE before p9, a superuser inside a FreeBSD jail configured with the non-default allow.mount permission could cause a race condition between the lookup of ".." and remounting a filesystem, allowing access to filesystem hierarchy outside of the jail.

Weakness: CWE-362 (Concurrent Execution using Shared Resource with Improper Synchronization)

## Which versions are affected by CVE-2020-25584?

It affects 1 product.


Products: Freebsd Freebsd.

## How do I fix CVE-2020-25584?

No fix has been published for CVE-2020-25584 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-25584 being exploited?

There is no known exploitation of CVE-2020-25584 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-2020-25584 and fix it if it is affected.

What it is: CVE-2020-25584 is a high-severity vulnerability in Freebsd Freebsd, published on 7 Apr 2021. 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-2020-25584 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-2020-25584/ (Markdown: https://insights.sbomify.com/CVE-2020-25584/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25584
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25584
- OSV: https://osv.dev/vulnerability/CVE-2020-25584

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-25584/
Summaries are generated and may contain mistakes; the official description above is the record.