alert http $EXTERNAL_NET any -> $HTTP_SERVERS any (msg:"ET WEB_SERVER Possible Apache Struts OGNL Expression Injection"; flow:to_server,established; http.uri; content:"|24 7b|"; content:"|25 7b|"; distance:0; content:"|7d|"; distance:0; pcre:"/\${\s*?%{/"; reference:cve,2013-2135; reference:bugtraq,60345; reference:url,cwiki.apache.org/confluence/display/WW/S2-015; classtype:web-application-attack; sid:2023535; rev:3; metadata:affected_product Apache_HTTP_server, attack_target Web_Server, created_at 2016_11_18, cve CVE_2013_2135, deployment Datacenter, performance_impact Low, confidence Medium, signature_severity Major, updated_at 2020_08_03;)