alert tcp $EXTERNAL_NET any -> $SMTP_SERVERS 25 (msg:"GPL SMTP MAIL FROM overflow attempt"; flow:to_server,established; content:"MAIL FROM"; nocase; isdataat:260; content:!"|0A|"; within:256; reference:bugtraq,10290; reference:bugtraq,7506; reference:cve,2004-0399; reference:url,www.guninski.com/exim1.html; classtype:attempted-admin; sid:2102590; rev:5; metadata:created_at 2010_09_23, confidence Medium, signature_severity Major, updated_at 2019_07_26;)