alert tcp $EXTERNAL_NET any -> $HOME_NET 53 (msg:"GPL DNS TCP inverse query overflow"; flow:to_server,established; byte_test:1,<,16,4; byte_test:1,&,8,4; isdataat:400; reference:bugtraq,134; reference:cve,1999-0009; classtype:attempted-admin; sid:2103153; rev:3; metadata:created_at 2010_09_23, signature_severity Informational, updated_at 2019_07_26;)