Log4J – What Does It Do?

You have probably heard of Log4Shell, the security vulnerability that has ‘earned’ itself a NIST rank of 10:

NIST Ranking
Source

In this post, I will show a really basic example of how this vulnerability actually works. I will walk you through some basic usage of the Log4J library and then show how some fairly basic inputs into this library can cause truly unexpected, and potentially disastrous, outcomes.