From f117a7c3eeac7e52a041d2fb3c6e12a05f0ab762 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Sat, 10 Dec 2022 08:26:39 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- build-openssl.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/build-openssl.py b/build-openssl.py index 2b2f547f..a02ed500 100755 --- a/build-openssl.py +++ b/build-openssl.py @@ -50,7 +50,26 @@ def make_openssl_temp_dir(openssl_tar): shutil.rmtree(openssl_temp_dir) with tarfile.open(openssl_tar, 'r:gz') as tar: - tar.extractall(tempdir) + 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, tempdir) config_file = os.path.join(openssl_temp_dir, 'config') st = os.stat(config_file)