alert tcp $EXTERNAL_NET any -> $HOME_NET 21 (msg:"GPL FTP USER format string attempt"; flow:established,to_server; content:"USER"; nocase; pcre:"/^USER\s[^\n]*?%[^\n]*?%/smi"; reference:bugtraq,7474; reference:bugtraq,7776; reference:bugtraq,9262; reference:bugtraq,9402; reference:bugtraq,9600; reference:bugtraq,9800; reference:cve,2004-0277; reference:nessus,10041; reference:nessus,11687; classtype:misc-attack; sid:2102178; rev:18; metadata:created_at 2010_09_23, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_03_08;)