alert tcp $EXTERNAL_NET any -> $HOME_NET 21 (msg:"GPL FTP NLST overflow attempt"; flow:to_server,established; content:"NLST"; nocase; isdataat:100,relative; pcre:"/^NLST\s[^\n]{100}/smi"; reference:bugtraq,10184; reference:bugtraq,7909; reference:bugtraq,9675; reference:cve,1999-1544; classtype:attempted-admin; sid:2102374; rev:7; metadata:created_at 2010_09_23, cve CVE_1999_1544, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)