CVE-2022-20821 Cisco IOS XR Open Port

Exploited in the wild Medium 6.5 Published 26 May 2022 Updated 21 Oct 2025

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

Exploited in the wild: Since 23 May 2022
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

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

Which versions are affected by CVE-2022-20821?

It affects 1 product.

Products include 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.

All Cisco Ios Xr vulnerabilities

Sources

Also known as GHSA-6whc-cmc9-99q6.