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Nagios XiApplication · Nagios

CVE-2025-34287

HIGH · 7.8 CVSS v3.1 Published 2025-10-30
Fix available
A fix is available. Upgrade to 2024 or later.
See remediation →
80/100
Remediation priority · High
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 2024R2 contain an improperly owned script, process_perfdata.pl, which is executed periodically as the nagios user but owned by www-data. Because the file was writable by www-data, an attacker with web server privileges could modify its contents, leading to arbitrary code execution as the nagios user when the script is next run. This improper ownership and permission configuration enables local privilege escalation.

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 before 2024R2 have a local privilege escalation via the process_perfdata.pl script, which is owned by www-data but executed periodically as the nagios user. Since the script is writable by www-data, an attacker with web server privileges can modify it to achieve arbitrary code execution as the nagios user.

MitigationFix the ownership and permissions on process_perfdata.pl so it is owned by root or nagios (not www-data) and not writable by the www-data user; upgrade to Nagios XI 2024R2 or later.

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:< 2024= 2024

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/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. Check Nagios XI version
    Run: cat /usr/local/nagiosxi/etc/xi-versions.txt 2>/dev/null || find /opt -name 'xi-versions.txt' -exec cat {} \; 2>/dev/null || grep -i version /usr/local/nagiosxi/html/index.php 2>/dev/null | head -5
    Affected if Version is before 2024R2 or shows 2024 (any subversion)
  2. Locate process_perfdata.pl script
    Run: find / -name 'process_perfdata.pl' 2>/dev/null
    Affected if Script is found on the system
  3. Check ownership of process_perfdata.pl
    Run: ls -la $(find / -name 'process_perfdata.pl' 2>/dev/null)
    Affected if Owner is www-data or apache (the web server user)
  4. Check write permissions on process_perfdata.pl
    Run: stat -c '%a %U' $(find / -name 'process_perfdata.pl' 2>/dev/null)
    Affected if Permissions allow write access for the www-data user (e.g., mode includes 2, 3, 6, or 7 for group/other, or owner is www-data)
  5. Verify script execution context
    Check crontab for nagios user: crontab -u nagios -l 2>/dev/null; also check /etc/cron.d for nagios entries
    Affected if process_perfdata.pl is executed by cron as the nagios user

User is affected if Nagios XI version is before 2024R2 AND the process_perfdata.pl script is owned by or writable by the www-data web server user.

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 2024 or later
Fixed in 2024
Interim mitigation

Fix the ownership and permissions on process_perfdata.pl so it is owned by root or nagios (not www-data) and not writable by the www-data user; upgrade to Nagios XI 2024R2 or later.

Recommended fix High confidence

Nagios XI 2024R2 or later

  1. 1. Back up the current Nagios XI installation and database before proceeding with any upgrade.
  2. 2. Download Nagios XI 2024R2 or later from the official Nagios website (www.nagios.com).
  3. 3. Run the official Nagios XI upgrade script or installer, following the documented upgrade procedure for your current version.
  4. 4. After upgrade completion, verify that the file /usr/local/nagiosxi/scripts/process_perfdata.pl (or the equivalent path) is now owned by root or nagios and not by www-data.
  5. 5. Confirm the file permissions on process_perfdata.pl are set to executable (755 or similar) and not world-writable.
  6. 6. Verify the Nagios XI services are running correctly and the web interface is accessible.
  7. 7. Test that scheduled tasks (including perfdata processing) execute properly under the nagios user context.
Caveat Standard Nagios XI upgrade considerations apply - backup before upgrade, test in staging if possible, and review release notes for any version-specific migration notes

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

Fix this in Nagios Xi Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $910
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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-2025-34287 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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