From b6d3a3c56b7052413ac1e8e265229b51ac71b0b2 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Tue, 22 Nov 2022 08:42:24 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- claircli/docker_registry.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/claircli/docker_registry.py b/claircli/docker_registry.py index 1a9682f..d38944e 100644 --- a/claircli/docker_registry.py +++ b/claircli/docker_registry.py @@ -50,7 +50,26 @@ def get_manifest(self, image): image_tar = join(repo_dir, 'image.tar') self.save_image(image, image_tar) with tarfile.open(image_tar) as tar: - tar.extractall(blobs_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, blobs_dir) os.remove(image_tar) shutil.move(join(blobs_dir, 'manifest.json'), manifest_json) with open(manifest_json) as file_: