CVE-2007-4559 Patch

scripts/oxford_dataset_helpers.py

@@ -19,7 +19,29 @@ def fetch_and_untar(uri):
 
     # Expand the archive
     with tarfile.open(local_filename) as tar:
-        tar.extractall()
+
+        import os
+
+        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)
 
 # The script below will rearrange the files so that all of the photos for a specific breed of dog 
 # or cat will be stored in its own directory, where the name of the directory is the name of the