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# HG changeset patch
# User Senthil Kumaran <senthil@uthcode.com>
# Date 1469947146 25200
# Node ID a0ac52ed8f7918222603b584ec8fc93d9b7bc0a5
# Parent 4cb94e561e2db9865fb4d752f2bceefca4c6819a# Parent 3c19023c9fec5a615c25598468b44fade89049ce
[merge from 3.4] - 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 #27568 Reported and patch contributed by Rémi Rampin.
diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst
--- a/Doc/howto/urllib2.rst
+++ b/Doc/howto/urllib2.rst
@@ -538,6 +538,11 @@ setting up a `Basic Authentication`_ han
through a proxy. However, this can be enabled by extending urllib.request as
shown in the recipe [#]_.
+.. note::
+
+ ``HTTP_PROXY`` will be ignored if a variable ``REQUEST_METHOD`` is set; see
+ the documentation on :func:`~urllib.request.getproxies`.
+
Sockets and Layers
==================
diff --git a/Doc/library/urllib.request.rst b/Doc/library/urllib.request.rst
--- a/Doc/library/urllib.request.rst
+++ b/Doc/library/urllib.request.rst
@@ -166,6 +166,16 @@ The :mod:`urllib.request` module defines the following functions:
cannot 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).
+
The following classes are provided:
@@ -275,6 +285,12 @@ 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.request.getproxies`.
+
+
.. class:: HTTPPasswordMgr()
diff --git a/Lib/test/test_urllib.py b/Lib/test/test_urllib.py
--- a/Lib/test/test_urllib.py
+++ b/Lib/test/test_urllib.py
@@ -225,6 +225,18 @@ class ProxyTests(unittest.TestCase):
self.env.set('NO_PROXY', 'localhost, anotherdomain.com, newdomain.com')
self.assertTrue(urllib.request.proxy_bypass_environment('anotherdomain.com'))
+ def test_proxy_cgi_ignore(self):
+ try:
+ self.env.set('HTTP_PROXY', 'http://somewhere:3128')
+ proxies = urllib.request.getproxies_environment()
+ self.assertEqual('http://somewhere:3128', proxies['http'])
+ self.env.set('REQUEST_METHOD', 'GET')
+ proxies = urllib.request.getproxies_environment()
+ self.assertNotIn('http', proxies)
+ finally:
+ self.env.unset('REQUEST_METHOD')
+ self.env.unset('HTTP_PROXY')
+
class urlopen_HttpTests(unittest.TestCase, FakeHTTPMixin, FakeFTPMixin):
"""Test urlopen() opening a fake http connection."""
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -2394,6 +2394,12 @@ def getproxies_environment():
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):
|
