CVE-2022-20821
MediumExploitedPublic exploitA 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.
Published May 26, 2022 · Updated Oct 28, 2025
Key Facts
Patch immediately- CVE-2022-20821 is a medium-severity vulnerability (CVSS 6.5 v3.1) affecting IOS Xr (Cisco), Cisco IOS XR Software.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 20, 2022. Public exploit code is available.
- EPSS estimates a 11% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
6.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
11%
Higher than 95.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2022-20821 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | May 23, 2022 | Jun 13, 2022 | Not reported |
| Industry KEV feed | May 20, 2022 | Jun 13, 2022 | Not reported |
| CIRCL KEV | May 23, 2022 | Jun 13, 2022 | Not reported |
| ENISA EUVD | May 23, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOS XrCisco | See advisory | n/a |
| Cisco IOS XR Software | >= n/a | n/a |
Timeline
Added to Industry KEV feed
May 20, 2022
Added to CISA KEV
May 23, 2022
Added to CIRCL KEV
May 23, 2022
Added to ENISA EUVD
May 23, 2022
Publicly disclosed
May 26, 2022
Last updated
Oct 28, 2025
Weakness Type
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
References
FAQ
Common Questions.
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.
Affected: IOS Xr (Cisco); Cisco IOS XR Software versions >= n/a. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since May 20, 2022.
Yes. It was added on May 23, 2022 with a federal remediation due date of Jun 13, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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