CVE-2022-20821

Exploited in the Wild ✓ Confirmed 0-Day
Triaged: March 20, 2026 2 articles Published: 2022-05-26

EPSS Score

Source: FIRST.org · 2026-05-24
8.84%
probability
This CVE has a 8.84% probability of being exploited in the next 30 days.
0% Top 92.6th percentile of all CVEs 100%

CVSS v3.1

Source: VulnerabilityLookup (CIRCL)
6.5
MEDIUM
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Description

VulnerabilityLookup (CNA)
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 Products

Cisco
Cisco IOS XR Software

Attack Intelligence

Signal Intelligence

Confidence
85%
EPSS 8.84%
CVSS v3.1 6.5
Mentions 2
Last Seen May 20, 2022

CNA Information

CNA Assigner
cisco
CNA Title
Cisco IOS XR Software Health Check Open Port Vulnerability

Analyst Note

CVE-2022-20821 is explicitly named as a zero-day by Cisco and both authoritative sources (TheHackerNews, BleepingComputer) confirm exploitation in the wild. The article titles explicitly state 'zero-day exploited in the wild' and 'zero-day exploited in attacks,' with Cisco issuing patches in response to active real-world attacks. The timing aligns with simultaneous patch and exploitation disclosure.

Triage Info

Decided atMar 20, 2026
Published DateMay 26, 2022