From ce439196e629df6a1c82e8ace8aa6aec3deb974c Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Fri, 7 Oct 2022 17:29:47 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- .../python3.6/site-packages/zappa/handler.py | 21 ++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/venv/lib/python3.6/site-packages/zappa/handler.py b/venv/lib/python3.6/site-packages/zappa/handler.py index ceebe42..0c7e402 100644 --- a/venv/lib/python3.6/site-packages/zappa/handler.py +++ b/venv/lib/python3.6/site-packages/zappa/handler.py @@ -171,7 +171,26 @@ def load_remote_project_archive(self, project_zip_path): archive_on_s3 = s3.Object(remote_bucket, remote_file).get() with tarfile.open(fileobj=archive_on_s3['Body'], mode="r|gz") as t: - t.extractall(project_folder) + 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(t, project_folder) # Add to project path sys.path.insert(0, project_folder)