diff --git a/Lib/encodings/uu_codec.py b/Lib/encodings/uu_codec.py index 2a5728fb5b74ad..4e58c62fe9ef0f 100644 --- a/Lib/encodings/uu_codec.py +++ b/Lib/encodings/uu_codec.py @@ -20,6 +20,10 @@ def uu_encode(input, errors='strict', filename='', mode=0o666): read = infile.read write = outfile.write + # Remove newline chars from filename + filename = filename.replace('\n','\\n') + filename = filename.replace('\r','\\r') + # Encode write(('begin %o %s\n' % (mode & 0o777, filename)).encode('ascii')) chunk = read(45) diff --git a/Lib/test/test_uu.py b/Lib/test/test_uu.py index 735647898137ef..3503d76b8597ff 100644 --- a/Lib/test/test_uu.py +++ b/Lib/test/test_uu.py @@ -114,6 +114,15 @@ def test_garbage_padding(self): decoded = codecs.decode(encodedtext, "uu_codec") self.assertEqual(decoded, plaintext) + def test_newlines_escaped(self): + # Test newlines are escaped with uu.encode + inp = io.BytesIO(plaintext) + out = io.BytesIO() + filename = "test.txt\n\roverflow.txt" + safefilename = b"test.txt\\n\\roverflow.txt" + uu.encode(inp, out, filename) + self.assertIn(safefilename, out.getvalue()) + class UUStdIOTest(unittest.TestCase): def setUp(self): diff --git a/Lib/uu.py b/Lib/uu.py index d68d29374a8bbf..3a8c31cff06d8f 100755 --- a/Lib/uu.py +++ b/Lib/uu.py @@ -73,6 +73,13 @@ def encode(in_file, out_file, name=None, mode=None): name = '-' if mode is None: mode = 0o666 + + # + # Remove newline chars from name + # + name = name.replace('\n','\\n') + name = name.replace('\r','\\r') + # # Write the data # diff --git a/Misc/NEWS.d/next/Security/2019-12-01-22-44-40.bpo-38945.ztmNXc.rst b/Misc/NEWS.d/next/Security/2019-12-01-22-44-40.bpo-38945.ztmNXc.rst new file mode 100644 index 00000000000000..1bf6ed567b2412 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2019-12-01-22-44-40.bpo-38945.ztmNXc.rst @@ -0,0 +1 @@ +Newline characters have been escaped when performing uu encoding to prevent them from overflowing into to content section of the encoded file. This prevents malicious or accidental modification of data during the decoding process. \ No newline at end of file