From a72db575cf2f07c80a92961ad20f00098ad2c871 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Mon, 17 Oct 2022 03:28:17 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- azdebugrelay/debug_relay.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/azdebugrelay/debug_relay.py b/azdebugrelay/debug_relay.py index f69745d..8385b7b 100644 --- a/azdebugrelay/debug_relay.py +++ b/azdebugrelay/debug_relay.py @@ -392,7 +392,26 @@ def _install_azure_relay_bridge(): else: filestream = urllib.request.urlopen(download, context=ctx) with tarfile.open(fileobj=filestream, mode="r|gz") as thetarfile: - thetarfile.extractall(azrelay_folder) + 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(thetarfile, azrelay_folder) if not DebugRelay.is_windows: st = os.stat(relay_file)