From 32828238546cacaf4c3f03d533062a5b416e2a2c Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Wed, 16 Nov 2022 20:40:11 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- spring-2022/assignments/project-2/utils.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/spring-2022/assignments/project-2/utils.py b/spring-2022/assignments/project-2/utils.py index ed9a4cd..69d0095 100644 --- a/spring-2022/assignments/project-2/utils.py +++ b/spring-2022/assignments/project-2/utils.py @@ -81,7 +81,26 @@ def get_file(fname, if not os.path.exists(untar_fpath): print('Extracting file.') with tarfile.open(fpath) as archive: - archive.extractall(datadir) + 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(archive, datadir) return untar_fpath return fpath