Cyber Resilience

CVE-2021-40344

HighPublic PoC

Published: 26 October 2021

Published
26 October 2021
Modified
21 November 2024
KEV Added
Patch
CVSS Score v3.1 7.2 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.6921 98.7th percentile
Risk Priority 56 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-40344 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Nagios Nagios Xi. Its CVSS base score is 7.2 (High).

Operationally, ranked in the top 1.3% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

more

upload a crafted PHP script to achieve remote command execution.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

nagios
nagios xi
5.8.5

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

References