Threats / Nagios / CVE-2021-25298
CVE-2021-25298
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-06-22
Nagios XI vulnerability
Nagios XI is vulnerable to OS command injection, allowing attackers to execute arbitrary commands on the affected server.
Verdict
Today item — known-exploited.
A command injection flaw in Nagios XI enables unauthenticated or low-privileged attackers to achieve remote code execution on the monitoring infrastructure, potentially compromising the entire monitored environment.
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 0.75196 — 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.
Weakness (CWE)
Mapped to CWE-78 OS Command Injection, CWE-138 CWE-138 — weakness family: Injection.CWE assignment from the public NVD record; the weakness class drives how the flaw is exploited.
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 inject OS commands into Nagios XI.
Business
Attackers gain code execution on critical monitoring infrastructure, bypassing security controls.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute arbitrary commands with the privileges of the Nagios XI process to establish persistence.
Business
The organization loses visibility into its infrastructure as the monitoring system is compromised.
3
Lateral reach — past segmentation narrative 3
Attacker
I pivot from the Nagios server to other systems on the network using credentials or lateral movement techniques.
Business
Attackers gain access to sensitive systems and data across the monitored environment.
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