Threats / Nagios / CVE-2021-25297
CVE-2021-25297
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
Nagios XI vulnerability
Nagios XI is vulnerable to OS command injection, allowing attackers to execute arbitrary commands on the affected server. The vulnerability has been exploited in the wild.
Verdict
Today item — known-exploited.
A remote attacker can inject and execute arbitrary operating system commands on a Nagios XI server, potentially compromising the monitoring infrastructure and gaining control of the host system.
CISA KEV Yes · 2022-01-184EPSS 0.56659 (verify live)5CVSS 8.8 (CISA)3CISA SSVC Exploitation: active · Automatable: no · Impact: total3Exploit Weaponized · public exploit · Metasploit module · nuclei template9
01
Is it exploitable?
— the evidence, ranked above the scoreReported exploitation
2 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 2022-01-18).
Probability (EPSS)
EPSS 0.56659 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 8.8 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) · Affected: Nagios, Nagios XI. Confirm exact fixed builds in the vendor advisory.CVSS — CISA-assigned via the ADP container (CVE.org), version 3.1; the CNA left no metrics, so CISA's own score is used ahead of NVD.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection, CWE-138 CWE-138 — weakness family: Injection.CWE assignment from the public NVD record (may be stale); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: no · Technical Impact: totalCISA'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 337 days after 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.
Public exploit available
Public exploit tooling is catalogued for this CVE (a functional/weaponized public exploit). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
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 craft a malicious input containing shell metacharacters to break out of intended command boundaries in Nagios XI.
Business
Monitoring infrastructure is compromised, creating blind spots in IT operations visibility.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary OS commands with the privileges of the Nagios XI process to establish persistence or lateral movement.
Business
Attacker gains foothold in critical infrastructure, enabling data theft, system manipulation, or further network compromise.
3
Lateral reach — past segmentation narrative 3
Attacker
I leverage command execution to exfiltrate sensitive configuration data or monitoring credentials stored on the server.
Business
Credentials and system intelligence are exposed, multiplying attack surface across monitored assets.
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 mitreCNA
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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