CVE-2022-20821 | Cisco IOS XR Software Health Check Open Port Vulnerability
Exp
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.
Conclusion & alert: CVE-2022-20821 is rated Active Exploitation (78.4/100): CVSS Medium severity, with high exploitation likelihood (EPSS 8.84%, 92th percentile).Core evidence: CISA KEV confirms active exploitation (added 2022-05-23) affecting Cisco / IOS XR. a weakness (CWE-200) Unauthenticated remote administrative access may be possible.Mandatory action: The CISA remediation deadline has passed—treat as an emergency patch priority.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
CISA KEV Record for CVE-2022-20821
Name: Cisco IOS XR Open Port Vulnerability · CISA KEV detail
Exploit added: 2022-05-23
Action due: 2022-06-13
Required action: Apply updates per vendor instructions.
Exploit prediction scoring system (EPSS) score for CVE-2022-20821
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).