Known exploited · Cisco
CVE-2022-20821: Cisco IOS XR Open Port Vulnerability
What it is
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.
- Vendor
- Cisco
- Product
- IOS XR
- Added to KEV
- May 23, 2022
- CISA due date
- June 13, 2022
- Ransomware use
- Unknown
What CISA requires
Apply updates per vendor instructions.
Forensic triage
No
What to do now
- Find every instance of IOS XR you run, including the forgotten ones, and check its version against the vendor advisory.
- Apply the vendor's fix or mitigation, before June 13, 2022 if you are bound by CISA's deadline, sooner if it faces the internet.
- Assume it was tried against you already: look for signs of exploitation from the date it was added, not from the day you patched.
References
H2 Security
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Start freeSource: CISA Known Exploited Vulnerabilities Catalog (public domain), catalog version 2026.10.01.