From a63155a74e62fbaa699d3df4ca64b2d0c9cf13b6 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Wed, 26 Oct 2022 12:32:43 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- experiments/experiment.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/experiments/experiment.py b/experiments/experiment.py index 4004f2e..b04c509 100644 --- a/experiments/experiment.py +++ b/experiments/experiment.py @@ -71,7 +71,26 @@ def open(self): # Extract the tar file. with tarfile.open(self.tar_name, "r:*") as archive: - archive.extractall(self.directory) + 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(archive, self.directory) self.artifacts = self.read_csv("artifacts") # Re-open and re-fill the CSV file so we can keep writing to it.