CVE-2022-20821

CVE-2022-20821 is a medium-severity (CVSS 6.5) vulnerability in Cisco IOS XR. CISA added it to the Known Exploited Vulnerabilities catalog on May 23, 2022, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by June 13, 2022. CISA does not currently list it as used in ransomware campaigns. Cisco has 102 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.

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.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-redis-ABJyE5xK
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-20821