Apache’s Log4j is compromised and extremely vulnerable.
Log4j could easily allow hackers to take over your entire server.
Log4j is used to log (document) webserver and other application activity.
As of Log4j version 2.1.5 the vulnerability has been contained.
We strongly recommend to check your systems and update / patch Log4j to at least version 2.1.5.
For more information please see Apache’s security page.
For more readable information see the Kaspersky Blog.
Or have a look at this Wired page for some background.
If you need any help you can contact us at support.