CVE-2021-40344

7.2 HIGH

An issue was discovered in Nagios XI 5.8.5

Published: 2021-10-26 · Last updated: 2026-06-17

Severity and scoring

CVSS: 7.2 HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-434

Affected products

Vendor	Product
nagios	nagios_xi

Description

An issue was discovered in Nagios XI 5.8.5. In the Custom Includes section of the Admin panel, an administrator can upload files with arbitrary extensions as long as the MIME type corresponds to an image. Therefore it is possible to upload a crafted PHP script to achieve remote command execution.

Source: NVD

References

[NVD]https://nvd.nist.gov/vuln/detail/CVE-2021-40344
[Vendor advisory]https://assets.nagios.com/downloads/nagiosxi/CHANGES-5.TXT
[Other]https://synacktiv.com
[Exploit reference]https://www.synacktiv.com/sites/default/files/2021-10/Nagios_XI_multiple_vulnerabilities_0.pdf
[Vendor advisory]https://assets.nagios.com/downloads/nagiosxi/CHANGES-5.TXT
[Other]https://synacktiv.com
[Exploit reference]https://www.synacktiv.com/sites/default/files/2021-10/Nagios_XI_multiple_vulnerabilities_0.pdf

Related CVEs

Same vendor

CVE-2021-40345 — An issue was discovered in Nagios XI 5.8.5 (7.2 HIGH)
CVE-2021-40343 — An issue was discovered in Nagios XI 5.8.5 (7.8 HIGH)
CVE-2021-38156 — In Nagios XI before 5.8.6, XSS exists in the dashboard page (/dashboards/#) when administrative users attempt to edit a dashboard (5.4 MEDIUM)
CVE-2021-3277 — Nagios XI 5.7.5 and earlier allows authenticated admins to upload arbitrary files due to improper validation of the rename functionality ... (7.2 HIGH)
CVE-2021-3273 — Nagios XI below 5.7 is affected by code injection in the /nagiosxi/admin/graphtemplates.php component (7.2 HIGH)

Same CWE

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CVE-2026-6933 — The Premmerce Dev Tools plugin for WordPress is vulnerable to Remote Code Execution via missing authorization in versions up to and inclu... (8.8 HIGH)
CVE-2026-40772 — Unauthenticated Arbitrary File Upload in GeekyBot <= 1.2.2 versions (10.0 CRITICAL)
CVE-2026-39591 — Subscriber Arbitrary File Upload in WP-BusinessDirectory <= 4.0.0 versions (9.9 CRITICAL)
CVE-2026-39527 — Subscriber Arbitrary File Upload in WpStream < 4.11.2 versions (5.4 MEDIUM)