From b075a95be3af4a9de576bbabd99ed5ca2b552a4a Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Mon, 12 Dec 2022 23:09:16 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- code/extract_data.py | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/code/extract_data.py b/code/extract_data.py index 2ce35f0..598c1e9 100644 --- a/code/extract_data.py +++ b/code/extract_data.py @@ -74,7 +74,29 @@ def main(): logging.info(' {}'.format(prefix)) subpath = 'data/{}/proceedings'.format(prefix) with tarfile.open(tarpath, 'r:gz') as datafh: - datafh.extractall(path=args.output_dir, + + 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(datafh, path=args.output_dir, members=[datafh.getmember("{}/order".format(subpath)), datafh.getmember("{}/id_map.txt".format(subpath))]) members=[datafh.getmember('{}/order'.format(subpath)), datafh.getmember('{}/id_map.txt'.format(subpath))])