Troubleshooting CVE-Check CVE-2021-44228 Log4j is crashing on Windows

This article helps troubleshoot why the CVE-Check for Log4j crashes on Windows systems.

LAST TESTED ON CHECKMK 2.0.0P1

Table of Contents

Problem

Together with a customer, we figured out a crash of the CVE-2021-44228 Log4j Checkmk from the Checkmk Exchange Site: https://exchange.checkmk.com/p/cve-2021-44228-log4j

Screenshot of CVE-2021-44228-log4j service in an Unknown state.

Screenshot of a crash report stating TypeError not supported between instances of tuple and int.


The problem seems to be the incomplete agent output:

<<<cve_2021_44228_log4j:sep(0):cached(1640096053,86400)>>>
2021-12-21T15:14:13+01:00
SCAN OPTIONS: --all-drives
<<<>>>


Solution

Let's debug this further on the Windows machine:

The Powershell script returns only the incomplete output. That's why we need to execute the log4j2-scan.exe

Screenshot of log4j2-scan.exe with a vcruntime104.dll was not found.

To solve this, you can use this manual: https://answers.microsoft.com/en-us/windows/forum/all/vcruntime140dll-was-not-found/f43d5afd-9239-4913-8f32-20e44a959e13