alert http $EXTERNAL_NET any -> $HOME_NET any (msg:"ET EXPLOIT [CORELIGHT] CrushFTP Auth Bypass Attempt (CVE-2025-31161)"; flow:established,to_server; http.header; content:"authorization|3a 20|"; nocase; content:"|20|credential|3d|"; nocase; pcre:"/^[^\x7e\x2f\x0d\x0a]+\x2f/R"; http.cookie; content:"CrushAuth|3d|"; fast_pattern; pcre:"/^[0-9]{13}_[a-zA-Z0-9]{26}/R"; content:"currentAuth="; byte_extract:4,0,c2f,relative; http.request_body; content:"c2f|3d|"; byte_test:4,=,c2f,0,relative; reference:url,github.com/Immersive-Labs-Sec/CVE-2025-31161/; reference:cve,2025-31161; classtype:attempted-admin; sid:2061619; rev:1; metadata:affected_product CrushFTP, attack_target Server, tls_state TLSDecrypt, created_at 2025_04_16, cve CVE_2025_31161, deployment Perimeter, deployment Internal, deployment SSLDecrypt, confidence High, signature_severity Major, tag Exploit, updated_at 2025_04_16, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)