Is CVE-2021-40905 actively exploited?

No active exploitation of CVE-2021-40905 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-40905 be exploited remotely?

Yes. CVE-2021-40905 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-40905?

CVE-2021-40905 has a CVSS score of 8.8 (HIGH).

HOME VULNERABILITIESCVE-2021-40905

HIGH

CVE-2021-40905

CWE-434Published: March 25, 2022· Updated: Jul 9, 2026

8.8

CVSS v3.1

Official Description

The web management console of CheckMK Enterprise Edition (versions 1.5.0 to 2.0.0p9) does not properly sanitise the uploading of ".mkp" files, which are Extension Packages, making remote code execution possible. Successful exploitation requires access to the web management interface, either with valid credentials or with a hijacked session of a user with administrator role. NOTE: the vendor states that this is the intended behavior: admins are supposed to be able to execute code in this manner.

NVD Source

Technical Analysis

CVE-2021-40905 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.8.