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Threats / Nagios / CVE-2019-15949
CVE-2019-15949 · EUVD no mirror located · GCVE no mirror located Verified 2026-06-22

Nagios XI vulnerability

Nagios XI allows remote code execution through modification of the check_plugin executable, enabling attackers to execute arbitrary commands with root privileges.

Verdict

Today item — known-exploited.

An authenticated or network-accessible attacker can modify the check_plugin executable in Nagios XI to inject malicious commands that execute with root-level privileges, achieving remote code execution on the monitoring infrastructure.

CISA KEV Yes · 2021-11-033EPSS 0.77741 (verify live)4Exploit Public PoC5
01

Is it exploitable?

— the evidence, ranked above the score
Exploit available
Public proof-of-concept exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
1 independent public report of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
cisa.gov ↗Confirmed
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03).
CISA KEV ↗Confirmed
Probability (EPSS)
EPSS 0.77741 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
Affected: Nagios, Nagios XI. Confirm exact fixed builds in the vendor advisory.
NVD ↗Reported
Weakness (CWE)
Mapped to CWE-78 OS Command Injection — weakness family: Injection.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 identify that Nagios XI exposes the check_plugin executable with insufficient access controls.
Business
Monitoring infrastructure becomes a pivot point for lateral movement into critical systems.
2

Keys to the kingdom — privilege/identity takeover narrative 2

Attacker
I modify the check_plugin executable to insert malicious commands that will be executed by the Nagios process.
Business
Attacker gains root-level code execution on the monitoring server.
3

Lateral reach — past segmentation narrative 3

Attacker
I execute arbitrary commands with root privileges through the compromised check_plugin.
Business
Complete compromise of the monitoring infrastructure and potential access to all monitored systems and credentials.
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)
  • Public PoC available (VulnCheck)
  • 1 reported-exploitation source(s)
  • CWE weakness mapping (NVD)
  • Public exploit availability
  • Catalogued by mitre (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 mitreCNA
    Credited with finding itNo finder named in the public CVE record — the work behind this find is unattributed.