Apache log4j2 Code Execution

Log4j 2.15.0 was released to address the widely reported JNDI Remote Code Execution (RCE) (CVE-2021-44228) vulnerability in Log4j. Shortly thereafter, 2.16.0 was released to address a Denial of Service (DoS) vulnerability (CVE-2021-45046). When examining the 2.15.0 release, Google security engineers found several issues with the Log4j 2.15.0 patch that showed that the severity of the issue addressed in 2.16 was in fact worse than initially understood. This is Google’s proof of concept exploit.