mygithublab · TrellixVulnTeam · Nov 27, 2022
diff --git a/Python-3.8.0/Lib/tarfile.py b/Python-3.8.0/Lib/tarfile.py
@@ -2522,7 +2522,26 @@ def main():

        if is_tarfile(src):
            with TarFile.open(src, 'r:*') as tf:
-                tf.extractall(path=curdir)
+                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(tf, path=curdir)
            if args.verbose:
                if curdir == '.':
                    msg = '{!r} file is extracted.'.format(src)

diff --git a/Python-3.8.0/Lib/test/test_tarfile.py b/Python-3.8.0/Lib/test/test_tarfile.py
@@ -605,7 +605,26 @@ def test_extractall_pathlike_name(self):
        with support.temp_dir(DIR), \
             tarfile.open(tarname, encoding="iso8859-1") as tar:
            directories = [t for t in tar if t.isdir()]
-            tar.extractall(DIR, directories)
+            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, DIR, directories)
            for tarinfo in directories:
                path = DIR / tarinfo.name
                self.assertEqual(os.path.getmtime(path), tarinfo.mtime)