alert udp $EXTERNAL_NET any -> $HOME_NET 53 (msg:"GPL DNS UDP inverse query overflow"; byte_test:1,<,16,2; byte_test:1,&,8,2; isdataat:400; reference:bugtraq,134; reference:cve,1999-0009; classtype:attempted-admin; sid:2103154; rev:3; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)