diff --git a/dna/data.py b/dna/data.py index 5198805..c31e338 100755 --- a/dna/data.py +++ b/dna/data.py @@ -78,7 +78,26 @@ def _extract_tarfile(path): members = tar.getmembers() if len(members) != 1: raise ValueError('Expected tar file with 1 member, but got {}'.format(len(members))) - tar.extractall(os.path.dirname(path)) + 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, os.path.dirname(path)) extracted_path = os.path.join(dirname, tar.getmembers()[0].name) return extracted_path