# CVE-2022-20821: Cisco IOS XR Open Port

> Unauthenticated attackers can access a Redis instance via an open port to read and modify data, affecting Cisco IOS XR devices.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Yes, since 23 May 2022 (CISA KEV)
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 May 2022
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-6whc-cmc9-99q6

## What is CVE-2022-20821?

CVE-2022-20821 is a medium-severity vulnerability in Cisco Ios Xr, published on 26 May 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability in the health check RPM of Cisco IOS XR Software could allow an unauthenticated, remote attacker to access the Redis instance that is running within the NOSi container. This vulnerability exists because the health check RPM opens TCP port 6379 by default upon activation. An attacker could exploit this vulnerability by connecting to the Redis instance on the open port. A successful exploit could allow the attacker to write to the Redis in-memory database, write arbitrary files to the container filesystem, and retrieve information about the Redis database. Given the configuration of the sandboxed container that the Redis instance runs in, a remote attacker would be unable to execute remote code or abuse the integrity of the Cisco IOS XR Software host system.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2022-20821?

It affects 1 product.


Products: Cisco Ios Xr.

## How do I fix CVE-2022-20821?

No fix has been published for CVE-2022-20821 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 13 Jun 2022.

## Is CVE-2022-20821 being exploited?

Yes. Attackers have exploited CVE-2022-20821 in the wild since at least 23 May 2022.

## Other vulnerabilities in Cisco Ios Xr

- [CVE-2020-3118](https://insights.sbomify.com/CVE-2020-3118/): Cisco IOS XR Software Discovery Protocol Format String (high 8.8, exploited in the wild)
- [CVE-2020-3569](https://insights.sbomify.com/CVE-2020-3569/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2020-3566](https://insights.sbomify.com/CVE-2020-3566/): Cisco IOS XR Software DVMRP Memory Exhaustion (high 8.6, exploited in the wild)
- [CVE-2010-3035](https://insights.sbomify.com/CVE-2010-3035/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (high 7.5, exploited in the wild)
- [CVE-2009-2055](https://insights.sbomify.com/CVE-2009-2055/): Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service (medium 5.9, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-20821 and fix it if it is affected.

What it is: CVE-2022-20821 is a medium-severity vulnerability in Cisco Ios Xr, published on 26 May 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2022-20821 in the wild since at least 23 May 2022.

Affected product: Cisco Ios Xr. 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-2022-20821/ (Markdown: https://insights.sbomify.com/CVE-2022-20821/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-20821
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-20821
- OSV: https://osv.dev/vulnerability/CVE-2022-20821

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-20821/
Summaries are generated and may contain mistakes; the official description above is the record.