Apache Log4j StrSubstitutor Uncontrolled Recursion Denial-of-Service Vulnerability

This vulnerability allows remote attackers to create a denial-of-service condition on affected installations of Apache Log4j. Authentication is not required to exploit this vulnerability. The specific flaw exists within the StrSubstitutor class. The issue results from the lack of proper validation of user-supplied data, which can result in a resource exhaustion condition. An attacker can leverage this vulnerability to create a denial-of-service condition on the process.