Fix rapid7#6993, tnspoison_checker cleanup

Author: wvu

modules/auxiliary/scanner/oracle/tnspoison_checker.rb

@@ -42,22 +42,21 @@ def run_host(ip)
       send_packet = tns_packet("(CONNECT_DATA=(COMMAND=service_register_NSGR))")
       sock.put(send_packet)
       packet = sock.read(100)
-      if packet != nil
-          hex_packet = Rex::Text.to_hex(packet, prefix = ':')
-          split_hex = hex_packet.split(":")
-          find_packet = /\(ERROR_STACK=\(ERROR=/ === packet
-          #find_packet == true ? print_error("#{ip}:#{rport} is not vulnerable ") : print_good("#{ip}:#{rport} is vulnerable")
-          if find_packet == true #TNS Packet returned ERROR
-                print_error("#{ip}:#{rport} is not vulnerable")
-          elsif split_hex[5] == "02" #TNS Packet Type: ACCEPT
-                print_good("#{ip}:#{rport} is vulnerable")
-          elsif split_hex[5] == "04" #TNS Packet Type: REFUSE
-                print_error("#{ip}:#{rport} is not vulnerable")
-          else #All other TNS packet types or non-TNS packet type response cannot guarantee vulnerability
-                print_error("#{ip}:#{rport} might not be vulnerable")
-          end
-      else
+      if packet
+        hex_packet = Rex::Text.to_hex(packet, ':')
+        split_hex = hex_packet.split(':')
+        find_packet = /\(ERROR_STACK=\(ERROR=/ === packet
+        if find_packet == true #TNS Packet returned ERROR
+          print_error("#{ip}:#{rport} is not vulnerable")
+        elsif split_hex[5] == '02' #TNS Packet Type: ACCEPT
+          print_good("#{ip}:#{rport} is vulnerable")
+        elsif split_hex[5] == '04' #TNS Packet Type: REFUSE
           print_error("#{ip}:#{rport} is not vulnerable")
+        else #All other TNS packet types or non-TNS packet type response cannot guarantee vulnerability
+          print_error("#{ip}:#{rport} might not be vulnerable")
+        end
+      else
+        print_error("#{ip}:#{rport} is not vulnerable")
       end
       # TODO: Module should report_vuln if this finding is solid.
       rescue ::Rex::ConnectionError, ::Errno::EPIPE