alert http any any -> $HOME_NET any (
msg:"ET WEB_SPECIFIC_APPS Citrix Netscaler SAML RelayState Reflected Cross-Site Scripting (CVE-2025-12101)";
flow:established,to_server;
http.method;
content:"POST";
http.uri;
content:"/cgi/logout"; fast_pattern;
http.request_body;
content:"RelayState|3d|";
base64_decode:offset 0,relative;
base64_data;
pcre:"/(?:(?:\x0d|\x250[dD])(?:\x0a|\x250[aA])){2}.*?(?:on(?:(?:s(?:elec|ubmi)|rese)t|d(?:blclick|ragdrop)|(?:mouse|key)[a-z]+|c(?:hange|lick)|(?:un)?load|focus|blur|error)|s(?:cript|tyle\x3d))/";
reference:url,labs.watchtowr.com/is-it-citrixbleed4-well-no-is-it-good-also-no-citrix-netscalers-memory-leak-rxss-cve-2025-12101/;
reference:cve,2025-12101;
classtype:web-application-attack;
sid:2065742; rev:1;
metadata:affected_product Citrix, attack_target Server, tls_state TLSDecrypt, created_at 2025_11_12, cve CVE_2025_12101, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_11_12, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application;
target:dest_ip;
)