alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL FTP SITE EXEC format string attempt"; flow:to_server,established; content:"SITE"; nocase; content:"EXEC"; distance:0; nocase; pcre:"/^SITE\s+EXEC\s[^\n]*?%[^\n]*?%/smi"; classtype:bad-unknown; sid:2101971; rev:5; metadata:created_at 2010_09_23, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)