From 08094f16e242d5e6e7f4067e87925d716019098f Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Wed, 12 Oct 2022 14:00:07 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- access/resources/utils.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/access/resources/utils.py b/access/resources/utils.py index 1bb829b..f8507cb 100644 --- a/access/resources/utils.py +++ b/access/resources/utils.py @@ -102,7 +102,26 @@ def move_with_overwrite(source_path, target_path): def untar(compressed_path, output_dir): with tarfile.open(compressed_path) as f: - f.extractall(output_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, output_dir) def unzip(compressed_path, output_dir):