What is CVE-2021-40905?

CVE-2021-40905 is a high-severity vulnerability in Checkmk, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2022-03-25.

How severe is CVE-2021-40905?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2021-40905 known to be exploited?

10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Arbitrary file upload in Checkmk

CVE-2021-40905

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.

Vulnerability class: Unrestricted File Upload

EPSS: 0.030 (86.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Checkmk — versions 2.0.0
Tribe29 Checkmk
N/a — versions n/a

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

Public proof-of-concept exploits

References

af854a3a-2127-422b-91ae-364da2661108 (Product, x_refsource_MISC)
cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
cve@mitre.org

Frequently asked questions

What is CVE-2021-40905?: CVE-2021-40905 is a high-severity vulnerability in Checkmk, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2022-03-25.
How severe is CVE-2021-40905?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2021-40905 known to be exploited?: 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.