ET WEB_SPECIFIC_APPS OpenCATS Installer Config databaseConnectivity Command Injection Attempt (CVE-2026-27760)

alert http any any -> $HOME_NET any (
    msg:"ET WEB_SPECIFIC_APPS OpenCATS Installer Config databaseConnectivity Command Injection Attempt (CVE-2026-27760)";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/ajax.php|3f|"; startswith;
    content:"|3d|install|3a|ui"; fast_pattern;
    content:"|3d|databaseConnectivity";
    http.request_body;
    content:"|27 29 3b|";
    reference:url,chocapikk.com/posts/2026/opencats-installer-rce/;
    reference:cve,2026-27760;
    classtype:attempted-admin;
    sid:2069669; rev:1;
    metadata:affected_product OpenCATS, attack_target Web_Server, tls_state plaintext, created_at 2026_06_05, cve CVE_2026_27760, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_06_05, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)