From 27fa32595e211a37db2b18cc065a748ca74eb121 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Thu, 6 Oct 2022 10:11:22 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- ws/snapshot.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/ws/snapshot.py b/ws/snapshot.py index aa8410e..d3fcf57 100644 --- a/ws/snapshot.py +++ b/ws/snapshot.py @@ -67,7 +67,26 @@ def get_snapshot(version, target=None): # Untar the snapshot. if not path.exists(snapshot_file): with tarfile.open(snapshot_tarfile) as handle: - handle.extractall(snapshot_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(handle, snapshot_dir) # Return the compiler path. return snapshot_file