alert ftp $EXTERNAL_NET any -> $HOME_NET any (msg:"GPL FTP SITE NEWER attempt"; flow:to_server,established; content:"SITE"; nocase; content:"NEWER"; distance:1; nocase; pcre:"/^SITE\s+NEWER/smi"; reference:cve,1999-0880; reference:nessus,10319; classtype:attempted-dos; sid:2101864; rev:9; metadata:created_at 2010_09_23, cve CVE_1999_0880, signature_severity Unknown, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)