CVE-2022-20821: Cisco IOS XR Open Port Vulnerability

Vulnerability summary

CVE-2022-20821 is a medium (CVSS 6.5) vulnerability in Cisco IOS XR. It is known to be exploited: CISA lists it, first on 23-05-2022. EPSS estimates a 11.47% chance of exploitation in the next 30 days, higher than 95.9% of scored vulnerabilities.

Timeline

1. 23-05-2022
   Added to CISA KEVCisco IOS XR Open Port Vulnerability
2. 26-05-2022
   PublishedVulnerability first disclosed.
3. 13-06-2022
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

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.

• CWE-200Exposure of Sensitive Information to an Unauthorized ActorThe product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.