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Threats / Cisco / CVE-2022-20821
CVE-2022-20821 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

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 · 2022-05-233EPSS 0.1176 (verify live)4
01

Is it exploitable?

— the evidence, ranked above the score
Reported 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).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.1176 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Cisco, IOS XR. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-923 CWE-923.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
NVD ↗Reported
02

Who’s exploiting it?

— attribution turns risk into urgency
Attribution 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 board
1

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’t

Established (cited)

  • KEV listing (CISA)
  • EPSS probability (FIRST)
  • 3 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Catalogued by cisco (CNA)
  • Coverage gaps — stated, not hidden

  • No EUVD / GCVE mirror in feed — single-authority dependency for the identifier.
  • EPSS & exposure are time-varying; verify live at the source.
  • Threat-actor attribution not established from feed data — absence of a name is not absence of compromise.
  • No finder/reporter credit recorded in the public CVE entry — the work behind this find is unattributed.
  • Disclosure & credit2
    Catalogued by ciscoCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.