Log4shell is the nickname provided to the Remote Code Execution (RCE) vulnerability that was disclosed in the Log4J utility managed by the Apache Foundation. Specifically, log4shell refers to CVE-2021-44228 and associated vulnerabilities. If an application is using a vulnerable version of log4j, an attacker can trigger the application to reach out to an attacker-controlled host which then deploys malicious code on the application’s server and gives the attacker control over the application and the server it sits on.