# CVE-2020-20813: Denial of service in n/a

> Remote attackers can cause a denial of service in OpenVPN by sending crafted reset packets to the control channel.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 22 Aug 2023
- **Updated:** 4 Oct 2024
- **Also known as:** GHSA-6mpq-5wjj-48jg, UBUNTU-CVE-2020-20813

## What is CVE-2020-20813?

CVE-2020-20813 is a high-severity denial of service vulnerability in n/a, published on 22 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Control Channel in OpenVPN 2.4.7 and earlier allows remote attackers to cause a denial of service via crafted reset packet.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2020-20813?

It affects 1 product.


Products: Openvpn Openvpn.

## How do I fix CVE-2020-20813?

No fix has been published for CVE-2020-20813 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-20813 being exploited?

There is no known exploitation of CVE-2020-20813 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2025-12106](https://insights.sbomify.com/CVE-2025-12106/): Memory corruption in OpenVPN (critical 9.1)
- [CVE-2024-5594](https://insights.sbomify.com/CVE-2024-5594/): Information disclosure in OpenVPN (critical 9.1)
- [CVE-2018-7544](https://insights.sbomify.com/CVE-2018-7544/): Cross-site request forgery in n/a (critical 9.1)
- [CVE-2006-1629](https://insights.sbomify.com/CVE-2006-1629/): Code injection in n/a (critical 9.0)
- [CVE-2024-4877](https://insights.sbomify.com/CVE-2024-4877/): Privilege escalation in OpenVPN (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-20813 and fix it if it is affected.

What it is: CVE-2020-20813 is a high-severity denial of service vulnerability in n/a, published on 22 Aug 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-20813 in the wild and no public exploit code.

Affected product: n/a. 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-2020-20813/ (Markdown: https://insights.sbomify.com/CVE-2020-20813/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-20813
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-20813
- OSV: https://osv.dev/vulnerability/CVE-2020-20813

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-20813/
Summaries are generated and may contain mistakes; the official description above is the record.