diff --git a/Lib/poplib.py b/Lib/poplib.py index 84ea88de46b..13e0f716e49 100644 --- a/Lib/poplib.py +++ b/Lib/poplib.py @@ -32,6 +32,12 @@ CR = b'\r' LF = b'\n' CRLF = CR+LF +# maximal line length when calling readline(). This is to prevent +# reading arbitrary lenght lines. RFC 1939 limits POP3 line length to +# 512 characters, including CRLF. We have selected 2048 just to be on +# the safe side. +_MAXLINE = 2048 + class POP3: @@ -107,7 +113,10 @@ class POP3: # Raise error_proto('-ERR EOF') if the connection is closed. def _getline(self): - line = self.file.readline() + line = self.file.readline(_MAXLINE + 1) + if len(line) > _MAXLINE: + raise error_proto('line too long') + if self._debugging > 1: print('*get*', repr(line)) if not line: raise error_proto('-ERR EOF') octets = len(line) diff --git a/Lib/test/test_poplib.py b/Lib/test/test_poplib.py index e3901b886ca..17b22611fa6 100644 --- a/Lib/test/test_poplib.py +++ b/Lib/test/test_poplib.py @@ -83,7 +83,7 @@ class DummyPOP3Handler(asynchat.async_chat): def cmd_list(self, arg): if arg: - self.push('+OK %s %s' %(arg, arg)) + self.push('+OK %s %s' % (arg, arg)) else: self.push('+OK') asynchat.async_chat.push(self, LIST_RESP) @@ -204,6 +204,10 @@ class TestPOP3Class(TestCase): foo = self.client.retr('foo') self.assertEqual(foo, expected) + def test_too_long_lines(self): + self.assertRaises(poplib.error_proto, self.client._shortcmd, + 'echo +%s' % ((poplib._MAXLINE + 10) * 'a')) + def test_dele(self): self.assertOK(self.client.dele('foo')) diff --git a/Misc/NEWS b/Misc/NEWS index 1de9c10cbc3..44b0e96410f 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,10 @@ What's New in Python 3.2.6? Library ------- +- Issue #16041: CVE-2013-1752: poplib: Limit maximum line lengths to 2048 to + prevent readline() calls from consuming too much memory. Patch by Jyrki + Pulliainen. + - Issue #16042: CVE-2013-1752: smtplib: Limit amount of data read by limiting the call to readline(). Original patch by Christian Heimes.