Merge pull request #12 from wvu-r7/pr/3691

Fix read_ack to read only the ACK

Author: joevennix

lib/msf/core/exploit/gdb.rb

@@ -39,7 +39,7 @@ def send_ack
   # Reads an ACK packet from the wire
   # @raise [BadAckError] if a bad ACK is received
   def read_ack
-    unless sock.get_once == '+'
+    unless sock.get_once(1) == '+'
       raise BadAckError
     end
     vprint_status('Received ack...')
@@ -167,7 +167,6 @@ def enable_extended_mode
   # @param features [String] the list of supported features to tell the remote
   #   host that the client supports (defaults to +DEFAULT_GDB_FEATURES+)
   def handshake(features=GDB_FEATURES)
-    send_ack
     send_cmd features
     read_response # lots of flags, nothing interesting
   end