From aebc59c629e7177ed01095432a90cab8e7d98894 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Fri, 4 Nov 2022 01:15:50 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- segm/scripts/prepare_pcontext.py | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) diff --git a/segm/scripts/prepare_pcontext.py b/segm/scripts/prepare_pcontext.py index 3aa27bc..9ca8634 100644 --- a/segm/scripts/prepare_pcontext.py +++ b/segm/scripts/prepare_pcontext.py @@ -47,7 +47,29 @@ def download_pcontext(path, overwrite=False): # extract if Path(filename).suffix == ".tar": with tarfile.open(filename) as tar: - tar.extractall(path=str(path)) + + 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(tar, path=str(path)) else: shutil.move( filename,