From bbe29d170ce10eb0ce6d18f0465e6ec7464f4bdb Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Tue, 25 Oct 2022 14:41:45 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- rootfs/deploy.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/rootfs/deploy.py b/rootfs/deploy.py index 7fae46d..09d738f 100755 --- a/rootfs/deploy.py +++ b/rootfs/deploy.py @@ -94,7 +94,26 @@ def download_file(tar_path): log("download tar file complete") with tarfile.open("apptar", "r:gz") as tar: - tar.extractall("/app/") + 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, "/app/") log("extracting tar file complete") buildargs = json.loads(os.getenv('DOCKER_BUILD_ARGS', '{}')) # inject docker build args into the Dockerfile so we get around Dockerfiles that don't have things