CVE-2021-40905 File upload in n/a
Administrators can upload malicious extension packages to the CheckMK web console, enabling remote code execution, though the vendor considers this intended behavior.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-40905?
CVE-2021-40905 is a high-severity vulnerability in Checkmk Checkmk, published on 25 Mar 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
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.
Weakness: CWE-434
Which versions are affected by CVE-2021-40905?
It affects 2 products.
Products include Checkmk Checkmk, Tribe29 Checkmk.
How do I fix CVE-2021-40905?
No fix has been published for CVE-2021-40905 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-40905 being exploited?
There is no known exploitation of CVE-2021-40905 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Checkmk Checkmk
- CVE-2025-39666 omd: Local privilege escalation when executing omd commands as root
- CVE-2024-8606 Fix 2FA bypass via RestAPI
- CVE-2022-46836 PHP code injection in watolib
- CVE-2025-32919 Privilege Escalation in Windows License plugin for Checkmk Windows Agent
- CVE-2024-28827 Privilege escalation in Windows agent
Sources
Also known as GHSA-83pm-xjc4-cg4w.