How severe is CVE-2022-20821?

CVE-2022-20821 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2022-20821?

Affected package information for CVE-2022-20821 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2022-20821?

No fixed version has been published for CVE-2022-20821 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2022-20821 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2022-20821, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2022-20821?

CVE-2022-20821 has an EPSS (Exploit Prediction Scoring System) score of 8.8%, placing it in the 93th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2022-20821 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2022-20821 (Cisco IOS XR Open Port Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2022-05-23. CISA required all US federal civilian agencies to remediate this vulnerability by 2022-06-13. The required action was: Apply updates per vendor instructions. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2022-20821?

CVE-2022-20821 is classified as Information Exposure (CWE-200). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2022-20821?

CVE-2022-20821 affects cisco ios xr. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2022-20821 published, and has it been updated?

CVE-2022-20821 was published on May 26, 2022 and was last updated on October 28, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2022-20821: IOS XR Information Exposure (Medium 6.5)

EPSS Exploitation Probability

via FIRST.org ↗

8.8%probability of exploitation in next 30 days

Lower Risk93th percentile0.00%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

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.

Affected Products

1 product · 1 configurations

OS

ios xrcisco

all

Frequently Asked Questions

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

O3 Security · Impact-Aware SCA

Is CVE-2022-20821 in your stack?

O3 detects CVE-2022-20821 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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