CVE-2021-40344

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 64.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-10-26 · updated 2026-06-17
Weakness: CWE-434

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.

Affected products

Nagios XI: 5.8.5

References

https://assets.nagios.com/downloads/nagiosxi/CHANGES-5.TXT
https://synacktiv.com
https://www.synacktiv.com/sites/default/files/2021-10/Nagios_XI_multiple_vulnerabilities_0.pdf
https://assets.nagios.com/downloads/nagiosxi/CHANGES-5.TXT
https://synacktiv.com
https://www.synacktiv.com/sites/default/files/2021-10/Nagios_XI_multiple_vulnerabilities_0.pdf

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