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Nagios XiApplication · Nagios

CVE-2020-36856

HIGH · 8.8 CVSS v3.1 Published 2025-10-30
Fix available
A fix is available. Upgrade to 5.6.14 or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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 XI versions prior to 5.6.14 contain an authenticated remote command execution vulnerability in the CCM command_test.php script. Insufficient validation of the `address` parameter allows an authenticated user with access to the Core Config Manager to inject shell metacharacters that are incorporated into backend command invocations. Successful exploitation enables arbitrary command execution with the privileges of the Nagios XI web application user and may be leveraged to execute commands on the underlying XI host, modify system configuration, or fully compromise the host.

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 XI versions prior to 5.6.14 contain an authenticated remote command execution vulnerability in the CCM command_test.php script. The application fails to properly validate the 'address' parameter, allowing authenticated users with Core Config Manager access to inject shell metacharacters into backend command invocations. This enables arbitrary command execution with the privileges of the Nagios XI web application user.

MitigationUpgrade to Nagios XI version 5.6.14 or later. If immediate patching is not possible, restrict access to the Core Config Manager to only trusted administrative users and consider network-level controls to limit exposure.

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:< 5.6.14

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
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

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
    Run the command: cat /usr/local/nagiosxi/etc/var/info.php or check /usr/local/nagiosxi/version.txt to find the installed Nagios XI version number
    Affected if The version listed is less than 5.6.14
  2. Confirm Nagios XI is the affected component
    Verify the installation is Nagios XI (the enterprise/web version), not just Nagios Core, by checking for the /usr/local/nagiosxi directory structure
    Affected if The system runs Nagios XI (enterprise edition) with the web interface components
  3. Check if Core Config Manager is accessible
    Log into the Nagios XI web interface and navigate to the Core Config Manager (CCM) module, typically found under the 'Config' menu or at /nagiosxi/ccm/
    Affected if You can access the CCM interface with your current credentials
  4. Verify the vulnerable script exists
    Check for the presence of command_test.php in the CCM directory: locate command_test.php or check /usr/local/nagiosxi/html/includes/components/ccm/ for the file
    Affected if The command_test.php file exists in the CCM directory
  5. Confirm user has CCM access
    Verify your user account has Core Config Manager privileges by checking your role in Nagios XI under Admin > Users or by attempting to access the CCM interface
    Affected if Your account has authenticated access to the Core Config Manager

You are affected if you are running Nagios XI version below 5.6.14, the CCM module is installed and accessible, and you have an authenticated user account with Core Config Manager privileges.

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 5.6.14 or later
Fixed in 5.6.14
Interim mitigation

Upgrade to Nagios XI version 5.6.14 or later. If immediate patching is not possible, restrict access to the Core Config Manager to only trusted administrative users and consider network-level controls to limit exposure.

Recommended fix High confidence

Nagios XI 5.6.14

  1. Back up the current Nagios XI installation and configuration before proceeding with any upgrade
  2. Download Nagios XI version 5.6.14 or later from the official Nagios website (www.nagios.com)
  3. Log in to the Nagios XI server as root or with sudo privileges
  4. Run the Nagios XI update/upgrade script, following the official upgrade documentation
  5. After upgrade completes, verify the version by checking the Nagios XI administration interface
  6. Confirm that the CCM (Core Config Manager) command_test.php has been updated and the address parameter is now properly validated
Caveat Standard upgrade precautions apply - test in staging first, ensure backups are valid, and review release notes for any configuration changes

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

Fix this in Nagios Xi Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.

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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-2020-36856 in production — separate from our analysis above.

No notes yet

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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