bpo-39017: Avoid infinite loop in the tarfile module (GH-21454)
Avoid infinite loop when reading specially crafted TAR files using the tarfile module
(CVE-2019-20907).
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index d60d35b..3ddeb97 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -429,6 +429,13 @@
with self.assertRaisesRegex(tarfile.ReadError, "unexpected end of data"):
tar.extractfile(t).read()
+ def test_length_zero_header(self):
+ # bpo-39017 (CVE-2019-20907): reading a zero-length header should fail
+ # with an exception
+ with self.assertRaisesRegex(tarfile.ReadError, "file could not be opened successfully"):
+ with tarfile.open(support.findfile('recursion.tar')) as tar:
+ pass
+
class MiscReadTestBase(CommonReadTest):
def requires_name_attribute(self):
pass