CVE-2025-34287: Nagios XI · Incorrect Permissions
Affects Nagios XISource CVE Database V5
Not known to be exploited · CVSS 8.4 High.
Data as of 26 Oct 2026, 07:57 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Nagios XI | Affected
| Fixed in– |
AI-suggested
To mitigate CVE-2025-34287, organizations should immediately upgrade Nagios XI to version 2024R2 or later where the issue is resolved. If upgrading is not immediately feasible, administrators should manually correct the ownership and permissions of the process_perfdata.pl script to ensure it is owned by the nagios user and not writable by the www-data user. Implement strict file system permissions to prevent unauthorized modifications by the web server user. Additionally, isolate the web server environment to limit the privileges of www-data and employ application whitelisting or integrity monitoring to detect unauthorized changes to critical scripts. Network segmentation should be used to restrict access to the Nagios XI server, and web server security should be hardened to prevent initial compromise. Regularly audit user privileges and monitor logs for suspicious activity related to script execution. Employ multi-factor authentication and limit web server access to trusted personnel. Finally, maintain an incident response plan that includes monitoring for exploitation attempts of this vulnerability.
Description
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.