alert tcp $EXTERNAL_NET any -> $SMTP_SERVERS 25 (msg:"GPL SMTP RCPT TO overflow"; flow:to_server,established; content:"rcpt to|3A|"; nocase; content:!"|0a|"; within:300; isdataat:300; pcre:"/^RCPT TO\x3a\s[^\n]{300}/ism"; reference:bugtraq,2283; reference:bugtraq,9696; reference:cve,2001-0260; classtype:attempted-admin; sid:2100654; rev:17; metadata:created_at 2010_09_23, cve CVE_2001_0260, signature_severity Unknown, updated_at 2019_07_26;)