Merge pull request #30 from TrellixVulnTeam/master

lidar/common.py

@@ -171,7 +171,26 @@ def download_from_url(url, out_file_name=None, out_dir=".", unzip=True, verbose=
             if verbose:
                 print("Unzipping {} ...".format(out_file_name))
             with tarfile.open(out_file_path, "r") as tar_ref:
-                tar_ref.extractall(out_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(tar_ref, out_dir)
             final_path = os.path.join(
                 os.path.abspath(out_dir), out_file_name.replace(".tart", "")
             )