From 256d7fa3a8c19d65182e60e02f6c2ea64c6a8cf8 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Sun, 9 Oct 2022 17:55:56 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- pyredex/unpacker.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/pyredex/unpacker.py b/pyredex/unpacker.py index ca7198b22a8..e4a023c97b5 100644 --- a/pyredex/unpacker.py +++ b/pyredex/unpacker.py @@ -556,7 +556,26 @@ def unpack_tar_xz(input: str, output_dir: str) -> None: with tarfile.open(name=input, mode="r:xz") as t: os.makedirs(output_dir, exist_ok=True) - t.extractall(output_dir) + 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(t, output_dir) class XZSDexMode(BaseDexMode):