Threats / Cisco / CVE-2022-20821
CVE-2022-20821
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
Cisco IOS XR vulnerability
Cisco IOS XR software health check exposes an unprotected Redis instance on TCP port 6379 by default, allowing unauthenticated remote access to the NOSi container.
Verdict
Today item — known-exploited.
An attacker can connect to the exposed Redis service without authentication to access or manipulate data within the NOSi container, potentially compromising network device integrity and operations.
CISA KEV Yes · 2022-05-235EPSS 0.12094 (verify live)6CVSS 6.53CISA SSVC Exploitation: active · Automatable: yes · Impact: partial4
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
3 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-05-23).
Probability (EPSS)
EPSS 0.12094 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 6.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N) · Affected: Cisco, IOS XR. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-200 Information Exposure — weakness family: Authorization / access control.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: partialCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog the same day the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I scan for open port 6379 and identify a Cisco IOS XR device running the health check service.
Business
Network infrastructure is exposed to reconnaissance and targeting by threat actors.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I connect to the unprotected Redis instance without credentials and query or modify stored data.
Business
Device configuration, operational state, and monitoring data become subject to unauthorized access or tampering.
3
Lateral reach — past segmentation narrative 3
Attacker
I inject malicious commands or corrupt Redis data to disrupt the health check function or NOSi container operations.
Business
Network device reliability and visibility are degraded, affecting service availability and operational control.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by ciscoCNA
Credited with finding itNo finder is named in the public CVE record or the scanned vendor advisory — attribution scoped to the sources checked.
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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