From 2909991b792fa427439e3968664b236ad55529d5 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Fri, 28 Oct 2022 06:58:06 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- code/download.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/code/download.py b/code/download.py index ff590fc..f2c54a6 100644 --- a/code/download.py +++ b/code/download.py @@ -38,7 +38,26 @@ def ensure_path(path): with tarfile.open(f"{path_to_test_data}", "r:") as tar: members = [tar_mem for tar_mem in tar.getmembers()] - tar.extractall(os.path.dirname(path_to_test_data), members=members) + 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, os.path.dirname(path_to_test_data), members=members) else: print("Test data already exists.")