ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2022-20821

Cisco IOS XR Open Port Vulnerability

Published May 20, 2022 · catalog updated Jun 16, 2026 · Cisco IOS XR

Patch now

CVE-2022-20821 is in the CISA known-exploited catalog, due Jun 13, 2022. Confirm Cisco IOS XR against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Gaps on this record

  • No version range is stored. A customer cannot check an installed version against this record.
Severity
Medium6.5
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
11.47%
Remediation
Remediation guidance
Affected products
cpe cisco/ios xr · vendor Cisco IOS XR

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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe cisco/ios xrversion unspecified
  • vendor Cisco IOS XRversion unspecified

How to fix CVE-2022-20821

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2022-20821 is in the CISA known-exploited catalog, due Jun 13, 2022. Confirm Cisco IOS XR against the vendor advisory and apply that fix. The CVSS score does not change the priority.

Which versions are affected?

Affected version ranges are not on this record. Apply updates per vendor instructions.

What should an analyst verify?

CWE-200: Exposure of Sensitive Information; CWE-923. EPSS 11.47%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Cisco security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. May 23, 2022 · Catalog

    Detected

    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

  2. May 23, 2022 · CISA KEV

    Known exploited

    Apply updates per vendor instructions.

  3. Jun 13, 2022 · CISA KEV

    Remediation due

    Apply updates per vendor instructions.

  4. Jun 16, 2026 · Catalog

    Updated

    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

Sources

  • CISA KEVConfirmed exploitationCVE-2022-20821

    Cisco IOS XR software health check opens TCP port 6379 by default on activation. An attacker can connect to the Redis instance on the open port and allow access to the Redis instance that is running within the NOSi container.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2022-20821

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2022-20821

    30-day exploitation probability 11.5%

    first.org
  • NIST NVDVulnerability recordCVE-2022-20821

    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 acti

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2022-20821

    Cisco IOS XR software health check opens TCP port 6379 by default on activation. An attacker can connect to the Redis instance on the open port and allow access to the Redis instance that is running within the NOSi container.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.