# CVE-2022-42917: Race condition in FRRouting

> A local attacker with service user privileges can escalate to root by exploiting a TOCTOU race condition in FRRouting's configuration handling.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:R/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:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 13 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** DEBIAN-CVE-2022-42917, GHSA-x36x-qpcf-qwfj, UBUNTU-CVE-2022-42917

## What is CVE-2022-42917?

CVE-2022-42917 is a medium-severity vulnerability in FRRouting, published on 13 Sep 2026. 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

In FRRouting FRR before 8.5, the service user (usually frr) can escalate its privileges to root by monitoring the configuration directory (/etc/frr) and replacing config files upon creation with, for example, symlinks to change the ownership of arbitrary files. This is a TOCTOU Race Condition caused by a combination of touch and chown.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2022-42917?


## How do I fix CVE-2022-42917?

Upgrade to a fixed version.

## Is CVE-2022-42917 being exploited?

There is no known exploitation of CVE-2022-42917 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-42917 and fix it if it is affected.

What it is: CVE-2022-42917 is a medium-severity vulnerability in FRRouting, published on 13 Sep 2026. 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-2022-42917 in the wild and no public exploit code.

Affected product: FRRouting. 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-2022-42917/ (Markdown: https://insights.sbomify.com/CVE-2022-42917/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-42917
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-42917
- OSV: https://osv.dev/vulnerability/CVE-2022-42917

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-42917/
Summaries are generated and may contain mistakes; the official description above is the record.