ET EXPLOIT Apache Struts RCE Attempt (CVE-2020-17530)

alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (
    msg:"ET EXPLOIT Apache Struts RCE Attempt (CVE-2020-17530)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.request_body;
    content:"=";
    pcre:"/^(%25|%)(%7b|{)(%28|\()(%23|#)/R";
    content:"instancemanager"; nocase; fast_pattern;
    pcre:"/^(%3d|=)(%23|#)application(%5b|\[)(%22|")org(%2e|\.)apache(%2e|\.)tomcat(%2e|\.)instancemanager(%22|")(%5d|\])(%29|\))(%2e|\.)(%28|\()(%23|#)(ognlstack|stack)(%3d|=)(%23|#)attr(%5b|\[)(%22|")com(%2e|\.)opensymphony(%2e|\.)xwork2(%2e|\.)util(%2e|\.)valuestack(%2e|\.)valuestack(%22|")(%5d|\])(%29|\))(%2e|\.)(%28|\()(%23|#)/Rsi";
    content:"bean"; distance:0; within:200;
    content:"java"; distance:0; within:400;
    content:"execute"; distance:0;
    pcre:"/^(%2e|\.)exec/Ri";
    reference:cve,2020-17530;
    classtype:attempted-admin;
    sid:2035009; rev:2;
    metadata:attack_target Server, created_at 2022_01_28, cve CVE_2020_17530, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2022_01_28, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
)