Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2022-20821

CVE-2022-20821MEDIUM

Cisco IOS XR Software Health Check Open Port Vulnerability

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  L  L  N    6.5   .1147   95.9   YES

AFFECTED
  Product                Versions  Fixed
  Cisco IOS XR Software  n/a –     —

TIMELINE
  Nov 2   Reserved by cisco
  May 23  Added to CISA KEV, remediation due 2022-06-13
  May 26  Published (CNA: cisco)

CWE-200 · CNA: cisco · CVSS v3.1 · 2 references · KEV due June 13, 2022

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
November 2, 2021	Reserved	Reserved by cisco
May 23, 2022	KEV ADDED	Added to CISA KEV, remediation due 2022-06-13
May 26, 2022	Published	Published (CNA: cisco)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
Cisco	Cisco IOS XR Software	—	n/a	—

Weaknesses

CWE-200

References (2)

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK [vendor-advisory, x_refsource_CISCO]
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-20821 [government-resource]

Authoritative record: CVE-2022-20821 at cve.org

Vendors: cisco

Weaknesses: CWE-200

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2022-20821 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.