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FusionApplication · Nagios

CVE-2018-25119

MEDIUM · 6.1 CVSS v3.1 Published 2025-10-30
Fix available
A fix is available. Upgrade to 4.1.5 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Nagios Fusion versions prior to 4.1.5 are vulnerable to cross-site scripting (XSS) via the "fusionwindow" parameter. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Nagios Fusion versions before 4.1.5 contain a reflected cross-site scripting (XSS) vulnerability in the 'fusionwindow' parameter. The application fails to properly validate or escape user-supplied input, allowing attackers to inject and execute arbitrary JavaScript in victims' browsers.

MitigationUpgrade to Nagios Fusion version 4.1.5 or later. Alternatively, implement proper input validation and output encoding for the fusionwindow parameter.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FusionApplication
Affected:< 4.1.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm Nagios Fusion is installed
    Check for Nagios Fusion installation by looking for its web directory (commonly /opt/nagios/fusion or /usr/local/nagios/fusion) or run: rpm -qa | grep -i fusion or dpkg -l | grep -i fusion
    Affected if Nagios Fusion is not installed on the system
  2. Identify installed Nagios Fusion version
    Check the version via package manager: rpm -q nagios-fusion or dpkg -s nagios-fusion | grep Version. Alternatively, check the web interface footer or login page for the version number.
    Affected if The installed version is lower than 4.1.5 (e.g., 4.1.4, 4.1.0, etc.) or cannot be determined but the package appears outdated
  3. Verify the fusionwindow parameter is exposed
    Access the Nagios Fusion web application and inspect whether the 'fusionwindow' parameter is accepted in HTTP requests (check the URL structure or form submissions). Use a browser or curl to test: curl 'http://<server>/nagiosfusion/index.php?fusionwindow=test'
    Affected if The application accepts and reflects the fusionwindow parameter in the response without sanitization
  4. Test for XSS in fusionwindow parameter
    Send a crafted request with a test payload in the fusionwindow parameter (e.g., fusionwindow=%3Cscript%3Ealert(1)%3C/script%3E) and verify if the script tag is reflected unescaped in the HTML response
    Affected if The payload is rendered as raw JavaScript in the page response rather than being HTML-encoded

You are affected if Nagios Fusion is installed with a version lower than 4.1.5 AND the web interface is accessible with the fusionwindow parameter reflecting unsanitized input.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.1.5 or later
Fixed in 4.1.5
Interim mitigation

Upgrade to Nagios Fusion version 4.1.5 or later. Alternatively, implement proper input validation and output encoding for the fusionwindow parameter.

Recommended fix Moderate confidence

Nagios Fusion 4.1.5 or later

  1. 1. Back up the current Nagios Fusion installation and all configuration files
  2. 2. Download Nagios Fusion version 4.1.5 or later from the official Nagios website (www.nagios.com)
  3. 3. Follow the official Nagios Fusion upgrade documentation to install the update
  4. 4. After upgrade, verify the 'fusionwindow' parameter input is now properly validated or escaped
  5. 5. Test that the application functions correctly after the upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Fusion Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2018-25119 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data