# CVE-2020-5894: Security feature bypass in NGINX Controller

> Attackers can hijack user sessions after logout because the NGINX Controller webserver fails to invalidate server-side session tokens.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 7 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-q676-x7h7-vq4f

## What is CVE-2020-5894?

CVE-2020-5894 is a high-severity vulnerability in NGINX Controller, published on 7 May 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

On versions 3.0.0-3.3.0, the NGINX Controller webserver does not invalidate the server-side session token after users log out.

Weakness: CWE-384 (Session Fixation)

## Which versions are affected by CVE-2020-5894?

It affects 1 product.


Products: F5 Nginx Controller.

## How do I fix CVE-2020-5894?

No fix has been published for CVE-2020-5894 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-5894 being exploited?

There is no known exploitation of CVE-2020-5894 in the wild and no public exploit code.

## Other vulnerabilities in NGINX Controller

- [CVE-2020-27730](https://insights.sbomify.com/CVE-2020-27730/): Path traversal in NGINX Controller (critical 9.8)
- [CVE-2020-5901](https://insights.sbomify.com/CVE-2020-5901/): Cross-site scripting in NGINX Controller (critical 9.6)
- [CVE-2020-5900](https://insights.sbomify.com/CVE-2020-5900/): Cross-site request forgery in NGINX Controller (high 8.8)
- [CVE-2020-5863](https://insights.sbomify.com/CVE-2020-5863/): Missing authorization in NGINX Controller (high 8.6)
- [CVE-2020-5867](https://insights.sbomify.com/CVE-2020-5867/): Supply chain in NGINX Controller (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-5894 and fix it if it is affected.

What it is: CVE-2020-5894 is a high-severity vulnerability in NGINX Controller, published on 7 May 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2020-5894 in the wild and no public exploit code.

Affected product: NGINX Controller. 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-2020-5894/ (Markdown: https://insights.sbomify.com/CVE-2020-5894/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-5894
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-5894
- OSV: https://osv.dev/vulnerability/CVE-2020-5894

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-5894/
Summaries are generated and may contain mistakes; the official description above is the record.