Apache Struts is a free and open-source framework used to build Java web applications. We looked into past several Remote Code Execution (RCE) vulnerabilities reported in Apache Struts, and observed that in most of them, attackers have used Object Graph Navigation Language (OGNL) expressions. The use of OGNL makes it easy to execute arbitrary code remotely because Apache Struts uses it for most of its processes.
Using OGNL, a researcher found a new remote code execution vulnerability in Apache Struts 2, designated as CVE-2017-5638. An exploit has been reported to be already in the wild; our own research and monitoring have also seen attacks using the vulnerability.Read More