From 42a59fb3395ae11a8b060a11fad37e0fadfeffff Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Thu, 3 Nov 2022 08:07:27 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- .../cifar10/download_utils.py | 21 ++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/Module02_YourFirstClassifier/nearest_neighbors/cifar10/download_utils.py b/Module02_YourFirstClassifier/nearest_neighbors/cifar10/download_utils.py index 2c1f0b8..8916ace 100644 --- a/Module02_YourFirstClassifier/nearest_neighbors/cifar10/download_utils.py +++ b/Module02_YourFirstClassifier/nearest_neighbors/cifar10/download_utils.py @@ -63,7 +63,26 @@ def unpickle(file): assert _md5_check(tmp_file) == md5_checksum, "md5 checksum did not match!.. deleting file" with tarfile.open(tmp_file, 'r:gz') as f: - f.extractall(tmp_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(f, tmp_dir) finally: if os.path.isfile(tmp_file): os.remove(tmp_file)