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 c9f05e5b760d92..c8709f7a0d6660 100644 --- a/Lib/test/test_uu.py +++ b/Lib/test/test_uu.py @@ -136,6 +136,15 @@ 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 9b1e5e607207f7..9f1f37f1a64101 100755 --- a/Lib/uu.py +++ b/Lib/uu.py @@ -73,6 +73,13 @@ def encode(in_file, out_file, name=None, mode=None, *, backtick=False): 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