On July 16th, 2013 Apache announced a vulnerability affecting Struts 2.0.0 through 2.3.15 (http://struts.apache.org/release/2.3.x/docs/s2-016.html) and recommended upgrading to 2.3.15.1 (http://struts.apache.org/download.cgi#struts23151).

This week I began to receive reports of scanning and exploitation of this vulnerability.  The first recorded exploit attempt was found from July 17th.  A metasploit module was released July 24th.  On August 12th I received a bulletin detailing exploit attempts targeting this vulnerability.