CVE-2022-20821: Cisco IOS XR Open Port Vulnerability
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.
Other sources
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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Disable or do not activate the Cisco IOS XR health check RPM to prevent it from opening TCP port 6379 on the NOSi container.
Cisco IOS XR health check RPM activation = disabled - Compensating control
Block or restrict network access to TCP port 6379 (Redis) exposed by the NOSi container — for example, add device ACLs or firewall rules or use network segmentation to prevent remote connections to the Redis instance.
Event History
Frequently Asked Questions
What is the vulnerability ID for the Cisco IOS XR Open Port Vulnerability?
The vulnerability ID for the Cisco IOS XR Open Port Vulnerability is CVE-2022-20821.
What is the severity of CVE-2022-20821?
The severity of CVE-2022-20821 is medium, with a severity value of 6.5.
How does the vulnerability in Cisco IOS XR Software occur?
The vulnerability occurs because the health check RPM of Cisco IOS XR Software opens TCP port 6379 by default upon activation.
What is the impact of the Cisco IOS XR Open Port Vulnerability?
The vulnerability allows an unauthenticated, remote attacker to access the Redis instance running within the NOSi container.
How can I fix the Cisco IOS XR Open Port Vulnerability?
It is recommended to apply the necessary updates or patches provided by Cisco to mitigate the vulnerability.