From fcf2f58b1ec8eaba2d3aa4c0c0b74513b31328b8 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Sat, 29 Oct 2022 03:06:15 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- mingw32/lib/python3.9/tarfile.py | 21 ++++++++++++++++++++- mingw32/lib/python3.9/test/test_tarfile.py | 21 ++++++++++++++++++++- 2 files changed, 40 insertions(+), 2 deletions(-) diff --git a/mingw32/lib/python3.9/tarfile.py b/mingw32/lib/python3.9/tarfile.py index 1d15612..98dd54b 100644 --- a/mingw32/lib/python3.9/tarfile.py +++ b/mingw32/lib/python3.9/tarfile.py @@ -2541,7 +2541,26 @@ def main(): if is_tarfile(src): with TarFile.open(src, 'r:*') as tf: - tf.extractall(path=curdir) + 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(tf, path=curdir) if args.verbose: if curdir == '.': msg = '{!r} file is extracted.'.format(src) diff --git a/mingw32/lib/python3.9/test/test_tarfile.py b/mingw32/lib/python3.9/test/test_tarfile.py index 6279309..56f7dfb 100644 --- a/mingw32/lib/python3.9/test/test_tarfile.py +++ b/mingw32/lib/python3.9/test/test_tarfile.py @@ -644,7 +644,26 @@ def test_extractall_pathlike_name(self): with support.temp_dir(DIR), \ tarfile.open(tarname, encoding="iso8859-1") as tar: directories = [t for t in tar if t.isdir()] - tar.extractall(DIR, directories) + 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, DIR, directories) for tarinfo in directories: path = DIR / tarinfo.name self.assertEqual(os.path.getmtime(path), tarinfo.mtime)