Merge pull request #412 from TrellixVulnTeam/master

CVE-2007-4559 Patch

arekit/contrib/utils/download.py

@@ -51,4 +51,23 @@ def download():
 
         target_filepath = __get_resource(local_name)
         with tarfile.open(target_filepath) as file:
-            file.extractall(__get_embedding_dir(target_filepath))
+            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(file, __get_embedding_dir(target_filepath))