ET WEB_SPECIFIC_APPS Sitecore CMS CSRFTOKEN Deserialization Remote Code Execution Attempt (CVE-2019-9874)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS Sitecore CMS CSRFTOKEN Deserialization Remote Code Execution Attempt (CVE-2019-9874)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/sitecore/shell/Applications/Security/CreateNewUser/CreateNewUser.aspx"; fast_pattern;
    http.cookie;
    content:"|5f 5f|CSRFCOOKIE|3d|";
    http.request_body;
    content:"|5f 5f|CSRFTOKEN|3d|"; startswith;
    pcre:"/^[a-zA-Z0-9\x2f\x2b\x3d]{32}/R";
    reference:cve,2019-9874;
    reference:url,www.synacktiv.com/ressources/advisories/Sitecore_CSRF_deserialize_RCE.pdf;
    classtype:attempted-admin;
    sid:2061119; rev:2;
    metadata:affected_product Sitecore_CMS, attack_target Web_Server, tls_state plaintext, created_at 2025_03_26, cve CVE_2019_9874, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag CISA_KEV, updated_at 2025_03_27, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)