CVE-2007-4559 Patch

app/black_spots/tasks/calculate_black_spots.py

@@ -116,7 +116,26 @@ def calculate_black_spots(history_length=datetime.timedelta(days=5 * 365 + 1), r
         shp_tar = RoadSegmentsShapefile.objects.get(uuid=segments_shp_uuid).shp_tgz.path
         with tarfile.open(shp_tar, "r:gz") as tar:
             # TODO: Extract only the combined segments file, not the entire tarball
-            tar.extractall(tar_output_dir)
+            def is_within_directory(directory, target):
+
+                abs_directory = os.path.abspath(directory)
+                abs_target = os.path.abspath(target)
+
+                prefix = os.path.commonprefix([abs_directory, abs_target])
+
+                return prefix == abs_directory
+
+            def safe_extract(tar, path=".", members=None, *, numeric_owner=False):
+
+                for member in tar.getmembers():
+                    member_path = os.path.join(path, member.name)
+                    if not is_within_directory(path, member_path):
+                        raise Exception("Attempted Path Traversal in Tar File")
+
+                tar.extractall(path, members, numeric_owner=numeric_owner) 
+
+
+            safe_extract(tar, tar_output_dir)
 
         logger.info("Performing blackspot calculations")
         segments_path = os.path.join(tar_output_dir, 'segments', COMBINED_SEGMENTS_SHP_NAME)

app/black_spots/tasks/generate_training_input.py

@@ -149,7 +149,26 @@ def get_data(records_csv_uuid, segments_shp_uuid, road_srid):
     try:
         # TODO: Extract only the combined segments file, not the entire tarball
         with tarfile.open(shp_tar, 'r:gz') as tar:
-            tar.extractall(tar_output_dir)
+            def is_within_directory(directory, target):
+
+                abs_directory = os.path.abspath(directory)
+                abs_target = os.path.abspath(target)
+
+                prefix = os.path.commonprefix([abs_directory, abs_target])
+
+                return prefix == abs_directory
+
+            def safe_extract(tar, path=".", members=None, *, numeric_owner=False):
+
+                for member in tar.getmembers():
+                    member_path = os.path.join(path, member.name)
+                    if not is_within_directory(path, member_path):
+                        raise Exception("Attempted Path Traversal in Tar File")
+
+                tar.extractall(path, members, numeric_owner=numeric_owner) 
+
+
+            safe_extract(tar, tar_output_dir)
 
         segments_path = os.path.join(tar_output_dir, 'segments', COMBINED_SEGMENTS_SHP_NAME)
         with fiona.open(segments_path) as segments: