ET WEB_SPECIFIC_APPS Citrix NetScaler Unauthenticated Remote Code Execution (CVE-2026-8452)

alert http any any -> [$HOME_NET,$HTTP_SERVERS] any (
    msg:"ET WEB_SPECIFIC_APPS Citrix NetScaler Unauthenticated Remote Code Execution (CVE-2026-8452)";
    flow:established,to_server;
    http.uri;
    content:"/cgi/samlauth"; fast_pattern;
    http.method;
    content:"POST";
    http.request_body;
    content:"SAMLResponse|3d|";
    base64_decode:relative;
    base64_data;
    content:"|3c|ds:SignedInfo|3e|";
    content:"PrefixList|3d 22|"; distance:0;
    pcre:"/^[^\x22]{2500,}\x22/R";
    reference:url,labs.watchtowr.com/youre-back-in-the-room-citrix-netscaler-pre-auth-rce-cve-2026-8452/;
    reference:cve,2026-8452;
    classtype:web-application-attack;
    sid:2071537; rev:1;
    metadata:affected_product Citrix, attack_target Server, tls_state TLSDecrypt, created_at 2026_08_14, cve CVE_2026_8452, deployment Perimeter, deployment Internal, confidence High, signature_severity Major, tag Exploit, updated_at 2026_08_14, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
    target:dest_ip;
)