| From cb25fbd5abc0f4eb07dbb8ea819e9c26bda4fc99 Mon Sep 17 00:00:00 2001 |
| From: Senthil Kumaran <senthil@uthcode.com> |
| Date: Sat, 30 Jul 2016 05:49:53 -0700 |
| Subject: [PATCH] python: fix CVE-2016-1000110 |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| Prevent HTTPoxy attack (CVE-2016-1000110) |
| |
| Ignore the HTTP_PROXY variable when REQUEST_METHOD environment is set, which |
| indicates that the script is in CGI mode. |
| |
| Issue reported and patch contributed by Rémi Rampin. |
| |
| Backport patch from https://hg.python.org/cpython/rev/ba915d561667/ |
| |
| Upstream-Status: Backport |
| CVE: CVE-2016-1000110 |
| Signed-off-by: Mingli Yu <Mingli.Yu@windriver.com> |
| --- |
| Doc/howto/urllib2.rst | 5 +++++ |
| Doc/library/urllib.rst | 10 ++++++++++ |
| Doc/library/urllib2.rst | 5 +++++ |
| Lib/test/test_urllib.py | 12 ++++++++++++ |
| Lib/urllib.py | 9 +++++++++ |
| Misc/ACKS | 1 + |
| Misc/NEWS | 4 ++++ |
| 7 files changed, 46 insertions(+) |
| |
| diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst |
| index 6bb06d4..5cf2c0c 100644 |
| --- a/Doc/howto/urllib2.rst |
| +++ b/Doc/howto/urllib2.rst |
| @@ -525,6 +525,11 @@ setting up a `Basic Authentication`_ handler: :: |
| through a proxy. However, this can be enabled by extending urllib2 as |
| shown in the recipe [#]_. |
| |
| +.. note:: |
| + |
| + ``HTTP_PROXY`` will be ignored if a variable ``REQUEST_METHOD`` is set; see |
| + the documentation on :func:`~urllib.getproxies`. |
| + |
| |
| Sockets and Layers |
| ================== |
| diff --git a/Doc/library/urllib.rst b/Doc/library/urllib.rst |
| index 3b5dc16..bddcba9 100644 |
| --- a/Doc/library/urllib.rst |
| +++ b/Doc/library/urllib.rst |
| @@ -295,6 +295,16 @@ Utility functions |
| If both lowercase and uppercase environment variables exist (and disagree), |
| lowercase is preferred. |
| |
| + .. note:: |
| + |
| + If the environment variable ``REQUEST_METHOD`` is set, which usually |
| + indicates your script is running in a CGI environment, the environment |
| + variable ``HTTP_PROXY`` (uppercase ``_PROXY``) will be ignored. This is |
| + because that variable can be injected by a client using the "Proxy:" |
| + HTTP header. If you need to use an HTTP proxy in a CGI environment, |
| + either use ``ProxyHandler`` explicitly, or make sure the variable name |
| + is in lowercase (or at least the ``_proxy`` suffix). |
| + |
| .. note:: |
| urllib also exposes certain utility functions like splittype, splithost and |
| others parsing URL into various components. But it is recommended to use |
| diff --git a/Doc/library/urllib2.rst b/Doc/library/urllib2.rst |
| index 8a4c80e..b808b98 100644 |
| --- a/Doc/library/urllib2.rst |
| +++ b/Doc/library/urllib2.rst |
| @@ -229,6 +229,11 @@ The following classes are provided: |
| |
| To disable autodetected proxy pass an empty dictionary. |
| |
| + .. note:: |
| + |
| + ``HTTP_PROXY`` will be ignored if a variable ``REQUEST_METHOD`` is set; |
| + see the documentation on :func:`~urllib.getproxies`. |
| + |
| |
| .. class:: HTTPPasswordMgr() |
| |
| diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py |
| index 434d533..27a1d38 100644 |
| --- a/Lib/test/test_urllib.py |
| +++ b/Lib/test/test_urllib.py |
| @@ -170,6 +170,18 @@ class ProxyTests(unittest.TestCase): |
| self.assertTrue(urllib.proxy_bypass_environment('anotherdomain.com:8888')) |
| self.assertTrue(urllib.proxy_bypass_environment('newdomain.com:1234')) |
| |
| + def test_proxy_cgi_ignore(self): |
| + try: |
| + self.env.set('HTTP_PROXY', 'http://somewhere:3128') |
| + proxies = urllib.getproxies_environment() |
| + self.assertEqual('http://somewhere:3128', proxies['http']) |
| + self.env.set('REQUEST_METHOD', 'GET') |
| + proxies = urllib.getproxies_environment() |
| + self.assertNotIn('http', proxies) |
| + finally: |
| + self.env.unset('REQUEST_METHOD') |
| + self.env.unset('HTTP_PROXY') |
| + |
| def test_proxy_bypass_environment_host_match(self): |
| bypass = urllib.proxy_bypass_environment |
| self.env.set('NO_PROXY', |
| diff --git a/Lib/urllib.py b/Lib/urllib.py |
| index 139fab9..c3ba2c9 100644 |
| --- a/Lib/urllib.py |
| +++ b/Lib/urllib.py |
| @@ -1380,12 +1380,21 @@ def getproxies_environment(): |
| If you need a different way, you can pass a proxies dictionary to the |
| [Fancy]URLopener constructor. |
| """ |
| + # Get all variables |
| proxies = {} |
| for name, value in os.environ.items(): |
| name = name.lower() |
| if value and name[-6:] == '_proxy': |
| proxies[name[:-6]] = value |
| |
| + # CVE-2016-1000110 - If we are running as CGI script, forget HTTP_PROXY |
| + # (non-all-lowercase) as it may be set from the web server by a "Proxy:" |
| + # header from the client |
| + # If "proxy" is lowercase, it will still be used thanks to the next block |
| + if 'REQUEST_METHOD' in os.environ: |
| + proxies.pop('http', None) |
| + |
| + # Get lowercase variables |
| for name, value in os.environ.items(): |
| if name[-6:] == '_proxy': |
| name = name.lower() |
| diff --git a/Misc/ACKS b/Misc/ACKS |
| index ee3a465..9c374b7 100644 |
| --- a/Misc/ACKS |
| +++ b/Misc/ACKS |
| @@ -1121,6 +1121,7 @@ Burton Radons |
| Jeff Ramnani |
| Varpu Rantala |
| Brodie Rao |
| +Rémi Rampin |
| Senko Rasic |
| Antti Rasinen |
| Nikolaus Rath |
| diff --git a/Misc/NEWS b/Misc/NEWS |
| index 4ab3a70..cc2f65b 100644 |
| --- a/Misc/NEWS |
| +++ b/Misc/NEWS |
| @@ -187,6 +187,10 @@ Library |
| - Issue #26644: Raise ValueError rather than SystemError when a negative |
| length is passed to SSLSocket.recv() or read(). |
| |
| +- Issue #27568: Prevent HTTPoxy attack (CVE-2016-1000110). Ignore the |
| + HTTP_PROXY variable when REQUEST_METHOD environment is set, which indicates |
| + that the script is in CGI mode. |
| + |
| - Issue #23804: Fix SSL recv(0) and read(0) methods to return zero bytes |
| instead of up to 1024. |
| |
| -- |
| 2.8.1 |
| |