From 00423ec01353aa7d6a369b208712be8035defd54 Mon Sep 17 00:00:00 2001 From: TrellixVulnTeam Date: Mon, 28 Nov 2022 23:51:33 +0000 Subject: [PATCH] Adding tarfile member sanitization to extractall() --- generate.py | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) diff --git a/generate.py b/generate.py index ecba14d7..2affb395 100755 --- a/generate.py +++ b/generate.py @@ -48,7 +48,26 @@ def download_llvm_lib(): unzip_llvm = not os.path.isfile(sentinel_target) if download_llvm or unzip_llvm: with tarfile.open(download_target) as f: - f.extractall(LLVM_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(f, LLVM_DIR) logger.info(f"ava-llvm unpacked to {CLANG_LIB_DIR}") with open(sentinel_target, "w") as f: logger.info(f"Sentinel file created at {sentinel_target}")