CVE-2007-4559 Patch (#315)

Adding tarfile member sanitization to extractall()

Co-authored-by: TrellixVulnTeam <kasimir.schulz@trellix.com>
Co-authored-by: Jason <jiangjiajun@baidu.com>
Co-authored-by: Zeyu Chen <chenzeyu01@baidu.com>

python/fastdeploy/download.py

@@ -137,7 +137,26 @@ def decompress(fname):
 
     if fname.find('.tar') >= 0 or fname.find('.tgz') >= 0:
         with tarfile.open(fname) as tf:
-            tf.extractall(path=fpath_tmp)
+            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) 
+
+
+            safe_extract(tf, path=fpath_tmp)
     elif fname.find('.zip') >= 0:
         with zipfile.ZipFile(fname) as zf:
             zf.extractall(path=fpath_tmp)