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Nagios XiApplication · Nagios

CVE-2023-40932

MEDIUM · 5.4 CVSS v3.1 Published 2023-09-19
Fix available
A fix is available. Upgrade to 5.11.2 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

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
A Cross-site scripting (XSS) vulnerability in Nagios XI version 5.11.1 and below allows authenticated attackers with access to the custom logo component to inject arbitrary javascript or HTML via the alt-text field. This affects all pages containing the navbar including the login page which means the attacker is able to to steal plaintext credentials.

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

A stored Cross-Site Scripting (XSS) vulnerability exists in Nagios XI version 5.11.1 and below within the custom logo component's alt-text field. Authenticated attackers with access to this component can inject malicious JavaScript or HTML that persists across all pages containing the navbar, including the login page, enabling credential theft.

MitigationUpgrade Nagios XI to version 5.11.2 or later which contains the patched version. Until patched, restrict access to the custom logo component to trusted administrators only.

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
Nagios XiApplication
Affected:< 5.11.2

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
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/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. Identify Nagios XI installation and version
    Check the Nagios XI version by accessing the admin interface, reviewing /usr/local/nagiosxi/html/menu.php or /usr/local/nagiosxi/etc/backend.ini, or running: cat /usr/local/nagiosxi/var/nagiosxi.lock
    Affected if The installed version is 5.11.1 or below (any version < 5.11.2)
  2. Verify access to custom logo component
    Log into Nagios XI as an administrator and navigate to Admin > System Settings > Branding/Logo Settings, or check if the path /nagiosxi/admin/branding.php is accessible
    Affected if The user has administrator access to the custom logo/branding configuration panel
  3. Inspect custom logo alt-text field
    In the branding settings panel, examine the 'Custom Logo Alt Text' or 'Alt Text' field associated with any uploaded custom logo
    Affected if The alt-text field contains unsanitized HTML or JavaScript (e.g., <script> tags, event handlers like onload/onerror, javascript: URIs)
  4. Check navbar-included pages for injected content
    View the login page or any page containing the navbar and inspect the page source for the custom logo img tag; verify the alt attribute does not contain script tags or event handlers
    Affected if The alt-text field value appears unescaped in the HTML source of login page or other navbar-containing pages

You are affected if Nagios XI version is below 5.11.2 AND you have the custom logo component accessible with a potentially malicious alt-text value present in the configuration.

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 5.11.2 or later
Fixed in 5.11.2
Interim mitigation

Upgrade Nagios XI to version 5.11.2 or later which contains the patched version. Until patched, restrict access to the custom logo component to trusted administrators only.

Recommended fix High confidence

Nagios Xi 5.11.2

  1. Log into the Nagios Xi server with administrator credentials
  2. Backup the current Nagios Xi configuration and database before proceeding with any upgrade
  3. Download Nagios Xi version 5.11.2 or later from the official Nagios website (www.nagios.com) or your Nagios customer portal
  4. Run the official Nagios Xi upgrade script or use the web-based upgrade interface (Admin > System > Upgrade Xi)
  5. Follow the on-screen prompts to complete the upgrade process
  6. After upgrade, verify the version number matches the fixed release (5.11.2 or higher) in Admin > System > System Information
  7. Clear browser cache and test that the custom logo component in Admin > System > Custom Logo is functioning correctly
  8. Verify the fix by confirming that HTML/JavaScript in the alt-text field is properly escaped and not executed
Caveat Standard Nagios Xi upgrade - review release notes for any configuration changes or plugin compatibility notes before upgrading production systems

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

Fix this in Nagios Xi Scoped from the published advisory
  • Consultation4.0 h
  • Implementation6.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,840
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,544.

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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-2023-40932 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