alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"ET EXPLOIT Apache Struts Possible OGNL Java WriteFile in URI"; flow:to_server,established; http.uri; content:"java.io.FileOutputStream"; nocase; content:".write"; distance:0; nocase; content:"sun.misc.BASE64Decoder"; nocase; reference:url,struts.apache.org/development/2.x/docs/s2-013.html; classtype:attempted-user; sid:2016959; rev:4; metadata:created_at 2013_06_01, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_24;)