CVE-2021-44228, also known as Log4Shell or LogJam, is an unauthenticated RCE vulnerability that allows complete system takeover on systems with Log4j 2.0-beta9 to 2.14.1 and it is being actively exploited. Log4j is used in numerous Java applications and is present in many services as a dependency in custom applications within organisations as well as a wide range of cloud services.