# CVE-2020-25860: Race condition in Pengutronix RAUC

> An attacker can exploit a race condition in the RAUC update client to bypass signature verification and install arbitrary code on the device.

- **Severity:** Medium 6.6 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-25860, GHSA-cgf3-h62j-w9vv, UBUNTU-CVE-2020-25860

## What is CVE-2020-25860?

CVE-2020-25860 is a medium-severity vulnerability in Pengutronix RAUC, published on 21 Dec 2020. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

The install.c module in the Pengutronix RAUC update client prior to version 1.5 has a Time-of-Check Time-of-Use vulnerability, where signature verification on an update file takes place before the file is reopened for installation. An attacker who can modify the update file just before it is reopened can install arbitrary code on the device.

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

## Which versions are affected by CVE-2020-25860?

It affects 1 product.


Products: Pengutronix Rauc.

## How do I fix CVE-2020-25860?

Upgrade to a fixed version.

## Is CVE-2020-25860 being exploited?

There is no known exploitation of CVE-2020-25860 in the wild and no public exploit code.

Public exploit code:

- integration examples for the CVE-2020-25860 fix (github_poc): https://github.com/rauc/rauc-1.5-integration

## Other vulnerabilities in Pengutronix RAUC

- [CVE-2026-34155](https://insights.sbomify.com/CVE-2026-34155/): RAUC: Improper Signing of Plain Bundles Exceeding 2 GiB (high 7.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-25860 and fix it if it is affected.

What it is: CVE-2020-25860 is a medium-severity vulnerability in Pengutronix RAUC, published on 21 Dec 2020. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-25860 in the wild and no public exploit code.

Affected product: Pengutronix RAUC. 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-2020-25860/ (Markdown: https://insights.sbomify.com/CVE-2020-25860/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-25860
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-25860
- OSV: https://osv.dev/vulnerability/CVE-2020-25860

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-25860/
Summaries are generated and may contain mistakes; the official description above is the record.