alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS CrushFTP WebInterface Alternative Channel Authentication Bypass (CVE-2025-54309) M2"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/WebInterface/function/"; fast_pattern; content:"command|3d|login"; http.header; content:"as2-to"; nocase; pcre:"/^[^\x0d\x0a]*?\x5ccrushadmin/R"; reference:url,reliaquest.com/blog/threat-spotlight-cve-2025-54309-crushftp-exploit/; reference:cve,2025-54309; classtype:attempted-admin; sid:2064044; rev:1; metadata:affected_product CrushFTP, attack_target Server, tls_state TLSDecrypt, created_at 2025_08_19, cve CVE_2025_54309, deployment Perimeter, deployment Internal, confidence Medium, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_08_19, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)