Hay problemas con los dos paquetes mencionados en el titulo, el primer error que me lanza ufw es el siguiente:

$ sudo ufw enable

ERROR: Couldn't determine iptables version

Ahora el error que me lanza al tratar de abrir gufw:

$ sudo gufw

Traceback (most recent call last):
  File "/usr/lib/python3.6/site-packages/gufw/gufw.py", line 28, in <module>
    controler = Controller()
  File "/usr/lib/python3.6/site-packages/gufw/gufw/controller.py", line 23, in __init__
    self.frontend = Frontend()
  File "/usr/lib/python3.6/site-packages/gufw/gufw/model/frontend.py", line 23, in __init__
    self.firewall = Firewall()
  File "/usr/lib/python3.6/site-packages/gufw/gufw/model/firewall.py", line 31, in __init__
    self.status = self.backend.get_status()
  File "/usr/lib/python3.6/site-packages/gufw/gufw/model/ufw_backend.py", line 50, in get_status
    if 'Status: active' in self._run_cmd([self.UFW_PATH, 'status'], True):
  File "/usr/lib/python3.6/site-packages/gufw/gufw/model/ufw_backend.py", line 35, in _run_cmd
    proc = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE, stderr=subprocess.PIPE, env={'LANG':'C'})
  File "/usr/lib/python3.6/subprocess.py", line 729, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.6/subprocess.py", line 1364, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No existe el fichero o el directorio: '/usr/sbin/ufw': '/usr/sbin/ufw'

Espero que alguien con el mismo problema lo haya podido solucionar, saludos!!