lib/cuckoo: fix unknown memory protection flags

This is a temporary fix because when processing the Linux memory
dumps it fails with an undefined value. Current it is incorrectly
parsing the dump, but this is useful to visualize the dumps.

Author: nalves599

lib/cuckoo/common/objects.py

@@ -796,7 +796,7 @@ def _prot_to_str(self, prot):
         if prot & PAGE_GUARD:
             return "G"
         prot &= 0xFF
-        return self.protmap[prot]
+        return self.protmap.get(prot, "UNKNOWN")
 
     def pretty_print(self):
         new_addr_space = copy.deepcopy(self.address_space)