From 3a184cc875709d4324d234a4b939d614a2c9bb0f Mon Sep 17 00:00:00 2001

From: Charalampos Stratakis <cstratak@redhat.com>

Date: Mon, 1 Aug 2016 11:20:11 +0200

Subject: [PATCH] =?UTF-8?q?Fix=20for=20CVE-2016-1000110=20http://bugs.pyth?=

 =?UTF-8?q?on.org/issue27568=20Based=20on=20the=20patch=20by=20R=C3=A9mi?=

 =?UTF-8?q?=20Rampin?=

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

---

 Doc/howto/urllib2.rst   |  5 +++++

 Doc/library/urllib.rst  | 10 ++++++++++

 Doc/library/urllib2.rst |  4 ++++

 Lib/test/test_urllib.py | 12 ++++++++++++

 Lib/urllib.py           |  9 +++++++++

 5 files changed, 40 insertions(+)

diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst

index f84bf08..6542846 100644

--- a/Doc/howto/urllib2.rst

+++ b/Doc/howto/urllib2.rst

@@ -523,6 +523,11 @@ 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 c7d200d..3b9876e 100644

--- a/Doc/library/urllib.rst

+++ b/Doc/library/urllib.rst

@@ -280,6 +280,16 @@ Utility functions

    find it, looks for proxy information from Mac OSX System Configuration for

    Mac OS X and Windows Systems Registry for Windows.

+    .. 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 24deeb4..46fce59 100644

--- a/Doc/library/urllib2.rst

+++ b/Doc/library/urllib2.rst

@@ -224,6 +224,10 @@ 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 3a273f8..3845012 100644

--- a/Lib/test/test_urllib.py

+++ b/Lib/test/test_urllib.py

@@ -161,6 +161,18 @@ class ProxyTests(unittest.TestCase):

         self.env.set('NO_PROXY', 'localhost, anotherdomain.com, newdomain.com')

         self.assertTrue(urllib.proxy_bypass_environment('anotherdomain.com'))

+    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')

+

 class urlopen_HttpTests(unittest.TestCase, FakeHTTPMixin):

     """Test urlopen() opening a fake http connection."""

diff --git a/Lib/urllib.py b/Lib/urllib.py

index f9655f9..9b31df1 100644

--- a/Lib/urllib.py

+++ b/Lib/urllib.py

@@ -1361,11 +1361,20 @@ def getproxies_environment():

     [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)

+

     return proxies

 def proxy_bypass_environment(host):

-- 

2.7.4